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  • 51.
    Ahuja, Rajeev
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Sun, Z
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Luo, Wei
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Ab initio investigation on the phase stability of Ti3SiC2, Ti3Si0.5Ge0.5C2 and2006Ingår i: High Pressure Research, Vol. 26, s. 127-Artikel i tidskrift (Refereegranskat)
  • 52.
    Airey, John
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik. Physics Education Research.
    Can you teach it in English? The Language Choice Debate in Swedish Higher Education.2004Ingår i: Integrating Content and Language: meeting the challenge of a multilingual higher education: proceedings of the ICL Conference, October 23-25 2003 / [ed] Robert Wilkinson, Maastricht: Universitaire Pers Maastricht , 2004, s. 97-108Konferensbidrag (Refereegranskat)
  • 53.
    Airey, John
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik. Physics Education Research.
    När undervisningsspråket blir engelska2006Ingår i: Språkvård, ISSN 0038-8440, nr 4, s. 20-25Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [sv]

    Engelska blir vanligare och vanligare som undervisningsspråk i högre utbildning. Vad händer med ämnesinlärningen när undervisningsspråket blir engelska? John Airey har undersökt svenska fysikstudenter. Det behövs många goda råd för att undervisningen ska fungera.

  • 54.
    Airey, John
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Physics Students' Experiences of the Disciplinary Discourse Encountered in Lectures in English and Swedish2006Licentiatavhandling, monografi (Övrigt vetenskapligt)
  • 55.
    Airey, John
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Fysikundervisningens didaktik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Teaching University Courses through the Medium of English: The current state of the art.2003Ingår i: Didaktikens mångfald Vol. 1, 2003, s. 11-18Konferensbidrag (Övrigt vetenskapligt)
  • 56.
    Airey, John
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Domert, Daniel
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Linder, Cedric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Representing disciplinary knowledge? Understanding students' experience of the equations presented to them in physics lectures2006Ingår i: EARLI SIG2 Conference, Text and Graphics Representations, University of Nottingham, England, 2006Konferensbidrag (Refereegranskat)
  • 57.
    Airey, John
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Fysikens didaktik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Linder, Cedric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Fysikens didaktik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Disciplinary learning in a second language: A case study from university physics.2007Ingår i: 12th European Conference for Research on Learning and Instruction, Budapest, Hungary, 2007Konferensbidrag (Refereegranskat)
  • 58.
    Airey, John
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik. Department of Human Sciences, University of Kalmar.
    Linder, Cedric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik. Department of Physics, University of the Western Cape, Cape Town, South Africa..
    Disciplinary learning in a second language: A case study from university physics2007Ingår i: Researching Content and Language Integration in Higher Education / [ed] Wilkinson, Robert and Zegers, Vera, Maastricht: Maastricht University Language Centre , 2007, s. 161-171Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    There is a popular movement within Swedish universities and university colleges towards delivery of courses and degree programmes through the medium of English. This is particularly true in natural science, engineering and medicine where such teaching has been commonplace for some time. However, the rationale for using English as the language of instruction appears to be more a pragmatic response to outside pressures rather than a conscious educational decision. This situation has recently been challenged with the publication of the report of the Parliamentary Committee for the Swedish Language, Mål i Mun, which discusses the effects of so called domain losses to English.

     

    This paper gives an overview of the continuing debate surrounding teaching through the medium of English, and examines some of the research carried out in this area. In contrast to the wealth of studies carried out in the pre-university school world, very few studies have been identified at university level. One conclusion is that little appears to be known about what goes on when Swedish university students are taught in English by Swedish lecturers. The paper concludes by suggesting a number of research questions that need to be addressed in order to better understand this area. This paper will be of interest to anyone who teaches, or plans to teach, university subjects through the medium of English.

  • 59.
    Airey, John
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Linder, Cedric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Language and the Experience of Learning University Physics in Sweden2006Ingår i: European journal of physics, ISSN 0143-0807, E-ISSN 1361-6404, Vol. 27, nr 3, s. 553-560Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This qualitative study explores the relationship between the lecturing language (English or Swedish) and the related learning experiences of 22 undergraduate physics students at two Swedish universities. Students attended lectures in both English and Swedish as part of their regular undergraduate programme. These lectures were videotaped and students were then interviewed about their learning experiences using selected excerpts of the video in a process of stimulated recall. The study finds that although the students initially report no difference in their experience of learning physics when taught in Swedish or English, there are in fact some important differences which become apparent during stimulated recall. The pedagogical implications of these differences are discussed.

  • 60.
    Airey, John
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Fysikundervisningens didaktik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Linder, Cedric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Fysikundervisningens didaktik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Language, Bandwidth and the Shared Space of Learning2004Ingår i: EARLI SIG 9 Conference, Phenomenography and Variation Theory Go to School, Göteborg, Sweden, 2004Konferensbidrag (Övrigt vetenskapligt)
  • 61.
    Airey, John
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Fysikens didaktik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Linder, Cedric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Fysikens didaktik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Languages, Modality and Disciplinary Knowledge.2006Ingår i: 2nd International Conference on Integrating Content and Language in Higher Education. University of Maastricht, Maastricht, Netherlands., 2006Konferensbidrag (Refereegranskat)
  • 62.
    Airey, John
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Fysikens didaktik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Linder, Cedric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Fysikens didaktik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Learning in a Second Language. Two Case Studies from University Physics.2006Ingår i: 2nd International Conference on Integrating Content and Language in Higher Education. University of Maastricht, Maastricht, Netherlands., 2006Konferensbidrag (Refereegranskat)
  • 63.
    Airey, John
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Fysikundervisningen didaktik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Linder, Cedric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Fysikundervisningen didaktik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysikundervisningen didaktik.
    Looking for Links between Learning and the Discursive Practices of University Science.2005Ingår i: 11th European Conference for Research on Learning and Instruction, Nicosia, Cyprus., 2005Konferensbidrag (Refereegranskat)
  • 64. Aksenov, V. L,
    et al.
    Jernekov, K. N.
    Khaidukov, Yu. N.
    Nikitenko, Yu. V.
    Petrenko, A. V.
    Proglyado, V. V.
    Andersson, Gabriella
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Institutionen för fysik och materialvetenskap, Fysik III.
    Wäppling, Roger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Institutionen för fysik och materialvetenskap, Fysik III.
    Interplay between superconductivity and ferromagnetism in Fe/V multilayered structure studied by polarized neutron reflectometry2005Ingår i: Physica B, Vol. 356, s. 9-Artikel i tidskrift (Refereegranskat)
  • 65. Alagia, M
    et al.
    Richter, R
    Stranges, S
    Agåker, Marcus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Institutionen för fysik och materialvetenskap, Fysik II.
    Ström, Magnus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Institutionen för fysik och materialvetenskap, Fysik II.
    Söderström, Johan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Institutionen för fysik och materialvetenskap, Fysik II.
    Såthe, Conny
    Institutionen för fysik och materialvetenskap, Fysik II.
    Feifel, Raimund
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Institutionen för fysik och materialvetenskap, Fysik II.
    Sorensen, Stacey
    de Fanis, A
    Ueda, K
    Fink, R
    Rubensson, Jan-Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. Institutionen för fysik och materialvetenskap, Fysik II.
    Core level ionization dynamics in small molecules studied by x-ray-emission threshold-electron coincidence spectroscopy2005Ingår i: Physical Review A, Vol. 71, nr 1Artikel i tidskrift (Refereegranskat)
  • 66. Alagia, Michele
    et al.
    Richter, Robert
    Stranges, Stefano
    Agåker, Marcus
    Ström, Magnus
    Söderström, Johan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Såthe, Conny
    Feifel, Raimund
    Sorensen, Stacey
    De Fanis, Alberto
    Core level ionization dynamics in small molecules studied by x-ray-emission threshold-electron coincidence spectroscopy2005Ingår i: Physical Review A, ISSN 1050-2947, Vol. 71, s. 012506-Artikel i tidskrift (Refereegranskat)
  • 67. Alarcón, H.
    et al.
    Hedlund, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysik I.
    Johansson, Erik M. J.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysik I.
    Rensmo, Håkan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysik I.
    Hagfeldt, Anders
    KTH, Fysikalisk kemi / Physical Chemistry.
    Boschloo, Gerrit K.
    KTH, Fysikalisk kemi / Physical Chemistry.
    Modification of nanostructured TiO2 electrodes by electrochemical Al3+ insertion: Effects on dye-sensitized solar cell performance2007Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 111, nr 35, s. 13267-13274Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nanostructured TiO2 films were modified by insertion with aluminum ions using an electrochemical process. After heat treatment these films were found suitable as electrodes in dye-sensitized solar cells. By means of a catechol adsorption test, as well as photoelectron spectroscopy (PES), it was demonstrated that the density of Ti atoms at the metal oxide/electrolyte interface is reduced after Al modification. There is, however, not a complete coverage of aluminum oxide onto the TiO2, but the results rather suggest either the formation of a mixed Al−Ti oxide surface layer or formation of a partial aluminum oxide coating. No new phase could, however, be detected. In solar cells incorporating Al-modified TiO2 electrodes, both electron lifetimes and electron transport times were increased. At high concentrations of inserted aluminum ions, the quantum efficiency for electron injection was significantly decreased. Results are discussed at the hand of different models:  A multiple trapping model, which can explain slower kinetics by the creation of additional traps during Al insertion, and a surface layer model, which can explain the reduced recombination rate, as well as the reduced injection efficiency, by the formation of a blocking layer.

  • 68.
    Alfredsson, Ylfi
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Åhlund, John
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Nilson, Katharina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Kjeldgaard, Lisbeth
    O´Shea, J. N.
    Theobald, J.
    Bao, Zhuo
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Mårtensson, Nils
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Sandell, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Puglia, Carla
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Siegbahn, Hans
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Phase and molecular orientation in H2Pc on conducting glass: characterization of two deposition methods2005Ingår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 493, nr 1-2, s. 13-19Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, metal-free phthalocyanine has been deposited on a conducting glass surface by two methods: by spreading the molecular powder directly on the substrate in air and by vapor sublimation under ultra-high vacuum conditions (evaporation). The films have been characterized by means of core level X-ray Photoemission Spectroscopy, X-ray Absorption Spectroscopy (XAS) and Ultra Violet and Visible absorption spectroscopy (UV-Vis). Our results show that the two deposition methods produce molecular overlayers in different polymorphic phases; the UV-Vis measurements indicate that the film obtained by powder deposition is of x-phase type whereas sublimation leads to an α-polymorph structure. The XAS results show that in the powder deposited film the molecules are mainly oriented parallel to the surface. This is opposite to the case of the vapor deposited film, where the molecules mainly are oriented orthogonal to the surface.

  • 69.
    Alfredsson, Ylvi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Electronic and Structural Properties of Thin Films of Phthalocyanines and Titanium Dioxide2005Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis is based on experimental studies in chemical physics. Titanium dioxide (TiO2) and phthalocyanine’s (Pc’s), interesting in many future perspectives, have been deposited as thin films and studied as follows. Information has been obtained on e.g. molecular orientation, crystal structure, depth profile of the chemical composition, electrochemical properties and electronic structure. This has been achieved by means of a combination of techniques: X-ray photoelectron spectroscopy (XPS), near edge x-ray absorption fine structure (NEXAFS), density functional theory calculations (DFT), UV-visible absorption spectroscopy (UVVIS) and cyclic voltammetry (CV).

    Metal-free phthalcyanine (H2Pc) has been shown to form films with different crystal structure and molecular orientation depending on deposition method, evaporation/sublimation or powder deposition, on commercial conducting glass (fluorine doped tin oxide, FTO), which is used e.g. in solar cells and organic light emitting devices (OLEDs). The unoccupied molecular orbitals are divided in x, y and z space coordinates of the molecule and also divided in inequivalent nitrogen components.

    The electronic structure is also studied for a sublimated titanyl phthalocyanine (TiOPc) film and related to the metal-free phthalocyanine. The ligand field around the titanium atom in TiOPc is compared with that of TiO2 to delineate the unoccupied levels recorded by means of x-ray absorption spectroscopy.

    Nanostructured TiO2 films were manufactured by screen printing/doctor blading on FTO. Such films were additionally covered with lutetium diphthalocyanine (LuPc2) by means of surface assembly from solution. LuPc2-, LuPc2+ and LuPc2H were identified and the stability of the electrochromic reactions in this system was monitored.

    Chemical vapor deposition (CVD) has been used to grow nanometer sized anatase TiO2 crystals on pre-oxidized Si (111) without formation of interfacial carbon and with an interface layer of the size of 15- 25Å. The interface layer was found to be amorphous TiSixOy with graded stoichiometry.

    Delarbeten
    1. Electrochromic Properties of bis(phthalocyaninato)lutetium(III) Sensitized Nanostructured Anatase TiO2 Thin Films
    Öppna denna publikation i ny flik eller fönster >>Electrochromic Properties of bis(phthalocyaninato)lutetium(III) Sensitized Nanostructured Anatase TiO2 Thin Films
    1999 Ingår i: Electrochemical and Solid-State Letters, Vol. 2, nr 12, s. 648-650Artikel i tidskrift (Refereegranskat) Published
    Identifikatorer
    urn:nbn:se:uu:diva-92646 (URN)
    Tillgänglig från: 2005-02-25 Skapad: 2005-02-25Bibliografiskt granskad
    2. Titanium dioxide thin film growth on silicon(III) by chemical vapor deposition of titanium(IV)isopropoxide
    Öppna denna publikation i ny flik eller fönster >>Titanium dioxide thin film growth on silicon(III) by chemical vapor deposition of titanium(IV)isopropoxide
    Visa övriga...
    2002 Ingår i: J. Appl. Phys., Vol. 92, nr 6, s. 3381-3387Artikel i tidskrift (Refereegranskat) Published
    Identifikatorer
    urn:nbn:se:uu:diva-92647 (URN)
    Tillgänglig från: 2005-02-25 Skapad: 2005-02-25Bibliografiskt granskad
    3. Metalorganic chemical vapor deposition of anatase titanium dioxide on Si: Modifying the interface by pre-oxidation
    Öppna denna publikation i ny flik eller fönster >>Metalorganic chemical vapor deposition of anatase titanium dioxide on Si: Modifying the interface by pre-oxidation
    Visa övriga...
    2003 Ingår i: Surface Science, Vol. 530, nr 1-2, s. 63-70Artikel i tidskrift (Refereegranskat) Published
    Identifikatorer
    urn:nbn:se:uu:diva-92648 (URN)
    Tillgänglig från: 2005-02-25 Skapad: 2005-02-25Bibliografiskt granskad
    4. Equivalent core-hole time-dependent density function theory calculations of carbon 1s shake-up states of phthalocyanine
    Öppna denna publikation i ny flik eller fönster >>Equivalent core-hole time-dependent density function theory calculations of carbon 1s shake-up states of phthalocyanine
    Visa övriga...
    2004 (Engelska)Ingår i: Phys. Rev. B, Vol. 70, nr 19, s. 195214-Artikel i tidskrift (Refereegranskat) Published
    Nationell ämneskategori
    Fysik
    Identifikatorer
    urn:nbn:se:uu:diva-92649 (URN)
    Tillgänglig från: 2005-02-25 Skapad: 2005-02-25 Senast uppdaterad: 2012-04-02Bibliografiskt granskad
    5. Phase and molecular orientation in H2Pc on conducting glass: characterization of two deposition methods
    Öppna denna publikation i ny flik eller fönster >>Phase and molecular orientation in H2Pc on conducting glass: characterization of two deposition methods
    Visa övriga...
    2005 (Engelska)Ingår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 493, nr 1-2, s. 13-19Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    In this study, metal-free phthalocyanine has been deposited on a conducting glass surface by two methods: by spreading the molecular powder directly on the substrate in air and by vapor sublimation under ultra-high vacuum conditions (evaporation). The films have been characterized by means of core level X-ray Photoemission Spectroscopy, X-ray Absorption Spectroscopy (XAS) and Ultra Violet and Visible absorption spectroscopy (UV-Vis). Our results show that the two deposition methods produce molecular overlayers in different polymorphic phases; the UV-Vis measurements indicate that the film obtained by powder deposition is of x-phase type whereas sublimation leads to an α-polymorph structure. The XAS results show that in the powder deposited film the molecules are mainly oriented parallel to the surface. This is opposite to the case of the vapor deposited film, where the molecules mainly are oriented orthogonal to the surface.

    Nyckelord
    Metal-free phthalocyanine, Deposition process, X-ray absorption spectroscopy, X-ray photoemission spectroscopy
    Nationell ämneskategori
    Fysik
    Identifikatorer
    urn:nbn:se:uu:diva-75981 (URN)10.1016/j.tsf.2005.05.012 (DOI)000233150700003 ()
    Tillgänglig från: 2006-02-22 Skapad: 2006-02-22 Senast uppdaterad: 2017-12-14Bibliografiskt granskad
    6. Electronic structure of a vapor-deposited metal-free phthalocyanine thin film
    Öppna denna publikation i ny flik eller fönster >>Electronic structure of a vapor-deposited metal-free phthalocyanine thin film
    Visa övriga...
    2005 (Engelska)Ingår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 122, nr 21, s. 214723-Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The electronic structure of a vapor-sublimated thin film of metal-free phthalocyanine(H2Pc) is studied experimentally and theoretically. An atom-specific picture of the occupied and unoccupied electronic states is obtained using x-ray-absorption spectroscopy (XAS), core- and valence-level x-ray photoelectron spectroscopy (XPS), and density-functional theory (DFT) calculations. The DFT calculations allow for an identification of the contributions from individual nitrogen atoms to the experimental N1sXAS and valence XPS spectra. This comprehensive study of metal-free phthalocyanine is relevant for the application of such molecules in molecular electronics and provides a solid foundation for identifying modifications in the electronic structure induced by various substituent groups.

    Nationell ämneskategori
    Fysik
    Identifikatorer
    urn:nbn:se:uu:diva-96196 (URN)10.1063/1.1924539 (DOI)
    Tillgänglig från: 2007-09-21 Skapad: 2007-09-21 Senast uppdaterad: 2017-12-14Bibliografiskt granskad
    7. Electronic structure of TiOPc thin film on conducting glass studied by means of X-ray and photoelectron spectroscopies
    Öppna denna publikation i ny flik eller fönster >>Electronic structure of TiOPc thin film on conducting glass studied by means of X-ray and photoelectron spectroscopies
    2009 (Engelska)Ingår i: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 174, nr 1-3, s. 50-54Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Thin films of TiOPc have been investigated using photoelectron   spectroscopy (PES) and X-ray spectroscopy (XAS). The results are   interpreted in terms of the local geometry around the metal center both   with regard to bonding and crystal field symmetry. Core and valence PES   have been found to be in accordance with the structural characteristics   of the TiOPc molecule. For resonant PES at the N1s and Ti2p edges,   information on the local electronic structure of the occupied molecular   orbitals has been obtained. Ti2p XAS was interpreted in terms of   five-fold coordination around the titanium atom for TiOPc of C-4V   symmetry. Angle-resolved N1s XAS suggests the molecular planes to order   preferentially parallel to the sample surface plane.

    Nyckelord
    Phthalocyanine, PES, XAS, Resonant PES, Molecular orientation
    Nationell ämneskategori
    Fysik
    Identifikatorer
    urn:nbn:se:uu:diva-92652 (URN)10.1016/j.elspec.2009.05.002 (DOI)000271347700009 ()
    Tillgänglig från: 2005-02-25 Skapad: 2005-02-25 Senast uppdaterad: 2017-12-14Bibliografiskt granskad
  • 70.
    Alfredsson, Ylvi
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Brena, Barbara
    Nilson, Katharina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Åhlund, John
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Kjeldgaard, Lisbeth
    Nyberg, Mats
    Luo, Yi
    Mårtensson, Nils
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Sandell, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Puglia, Carla
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Siegbahn, Hans
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Electronic structure of a vapor-deposited metal-free phthalocyanine thin film2005Ingår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 122, nr 21, s. 214723-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The electronic structure of a vapor-sublimated thin film of metal-free phthalocyanine(H2Pc) is studied experimentally and theoretically. An atom-specific picture of the occupied and unoccupied electronic states is obtained using x-ray-absorption spectroscopy (XAS), core- and valence-level x-ray photoelectron spectroscopy (XPS), and density-functional theory (DFT) calculations. The DFT calculations allow for an identification of the contributions from individual nitrogen atoms to the experimental N1sXAS and valence XPS spectra. This comprehensive study of metal-free phthalocyanine is relevant for the application of such molecules in molecular electronics and provides a solid foundation for identifying modifications in the electronic structure induced by various substituent groups.

  • 71. Alfredsson, Ylvi
    et al.
    Åhlund, John
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Nilson, Katharina
    Kjeldgaard, Lisbeth
    O'Shea, James N.
    Theobald, James
    Bao, Zhuo
    Mårtensson, Nils
    Sandell, Anders
    Puglia, Carla
    Phase and molecular orientation in metal-free phthalocyanine films on conducting glass: Characterization of two deposition methods2005Ingår i: Thin Solid Films, Vol. 493, s. 13-19Artikel i tidskrift (Refereegranskat)
  • 72. Alling, B.
    et al.
    Ruban, A. V.
    Karimi, A.
    Peil, Oleg E.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Simak, S. I.
    Hultman, L.
    Abrikosov, I. A.
    Mixing and decomposition thermodynamics of c-Ti1-xAlxN from first-principles calculations2007Ingår i: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 75, nr 4, s. 045123-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We describe an efficient first-principles method that can be used to calculate mixing enthalpies of transition metal nitrides with B1 structure and substitutional disorder at the metal sublattice. The technique is based on the density functional theory. The independent sublattice model is suggested for the treatment of disorder-induced local lattice relaxation effects. It supplements the description of the substitutional disorder within the coherent potential approximation. We demonstrate the excellent accuracy of the method by comparison with calculations performed by means of the projector augumented wave method on supercells constructed as special quasirandom structures. At the same time, the efficiency of the technique allows for total energy calculations on a very fine mesh of concentrations which enables a reliable calculation of the second concentration derivative of the alloy total energy. This is a first step towards first-principles predictions of concentrations and temperature intervals where the alloy decomposition proceeds via the spinodal mechanism. We thus calculate electronic structure, lattice parameter, and mixing enthalpies of the quasibinary alloy c-Ti1-xAlxN. The lattice parameter follows Vegard's law at low fractions of AlN but deviates increasingly with increasing Al content. We show that the asymmetry of the mixing enthalpy and its second concentration derivative is associated with substantial variations of the electronic structure with alloy composition. The phase diagram is constructed within the mean-field approximation.

  • 73.
    Almeida, J
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Ahuja, Rajeev
    Tuning structural, electronic and optical properties of BexZn1-xTe2006Ingår i: Applied Physics Letters, Vol. 89, s. 061913-Artikel i tidskrift (Refereegranskat)
  • 74.
    Almlöf, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi.
    Kristensen, Emma M. E.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Siegbahn, Hans
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Åqvist, Johan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi.
    Molecular dynamics study of heparin based coatings2008Ingår i: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 29, nr 33, s. 4463-4469Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Heparin based surface coatings can be used to improve the biocompatibility of metallic surfaces such as vascular stents. Here, we report molecular dynamics simulations of a macromolecular conjugate of heparin used to prepare such surfaces. The structural properties of the heparin conjugate are investigated for different degrees of hydration, to allow comparison with spectroscopic results. The simulations show that the polymer becomes more compact with an increasing degree of inter-chain interactions as the hydration increases. This is also accompanied by changes in the interaction patterns among the heparin chains, where counter ions become looser associated with the disaccharide units and their strong interactions can be partly replaced by water molecules and heparin hydroxyl groups. The structural information that can be obtained from computer simulations of this type of coatings can be very valuable for understanding and further development of functional interfaces, since very little is known experimentally regarding their detailed structural properties. (C) 2008 Elsevier Ltd. All rights reserved.

  • 75.
    Almstrom, H.
    et al.
    FOI.
    Bjarnholt, G.
    FOI.
    Golberg, S.
    Liberman, M.A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    On the Methods of Production of Ultrahigh Pulsed Magnetic Fields1996Ingår i: Seventh International Conference on Megagauss Magnetic Field Generation and Related Topics: Proceedings of Seventh International Conference on Megagauss Magnetic Field Generation and Related Topics, 1996Konferensbidrag (Refereegranskat)
  • 76.
    Almstrom, H.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Bjarnholt, G.
    Golberg, S.M.
    Liberman, M. A.
    On the methods of generation of ultrahigh magnetic field1998Ingår i: FOA-report FOA-R-98-00829-612--SERapport (Övrigt vetenskapligt)
  • 77.
    Almstrom, H.
    et al.
    FOI.
    Bjarnholt, G
    FOI.
    Golberg, S.M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Liberman, M.A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Electromagnetic Radiation from Magnetic Flux Compression Generators1996Ingår i: Seventh International Conference on Megagauss Magnetic Field Generation and Related Topics, 1996Konferensbidrag (Refereegranskat)
  • 78.
    Almstrom, H.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Bjarnholt, G.
    Golberg, S.M.
    Liberman, M.A.
    Numerical modeling of magnetic flux compresion by a cylindrical imploding ionizing shock wave1998Ingår i: FOA-report FOA-R-98-00830-612--SERapport (Övrigt vetenskapligt)
  • 79.
    Ambrosch-Draxl, C
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. CONDENSED MATTER THEORY GROUP.
    Korzhavyi, PA
    Johansson, B
    First-Principles Study of Oxygen Ordering in YBa2Cu3O7-x2000Ingår i: Physica C, Vol. 341-348, s. 1997-1998Artikel i tidskrift (Refereegranskat)
  • 80.
    Amerioun S, Simak SI, Haussermann U
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen. THEORETICAL MAGNETISM AND CONDENSED MATTER THEORY.
    Laves-phase structural changes in the system CaAl2-Mg-x(x)2003Ingår i: INORGANIC CHEMISTRY, Vol. 42, nr 5, s. 1467-Artikel i tidskrift (Refereegranskat)
  • 81.
    Amft, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Oppeneer, Peter M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Calculated magneto-optical Kerr spectra of the half-Heusler compounds AuMnX (X = In, Sn, Sb)2007Ingår i: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 19, nr 31, s. 315216-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ferromagnetic ground states of the half-Heusler compounds AuMnX (X ≤ In, Sn, Sb) have been calculated in the framework of the local spin-density approximation (LSDA) to density functional theory (DFT). AuMnSn is computed to be a half-metallic ferromagnet, whereas AuMnIn and AuMnSb are not half-metallic, due to their different band filling. The computed relativistic electronic structures served as inputs to calculate the magneto-optical Kerr rotations and ellipticities for all three materials. In the case of AuMnSn the largest, zero-temperature, polar Kerr rotation has been found to be -0.45° at about 1eV photon energy. The computed MOKE spectra of AuMnSn are in qualitative agreement with recent experiments. The largest Kerr rotations of AuMnIn and AuMnSb have been calculated to be +0.64° at 4.3eV and -0.85° at 0.9eV, respectively.

  • 82.
    Amusia, MY
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Baltenkov, AS
    Chernysheva, LV
    Felfli, Z
    Msezane, AZ
    Nordgren, J
    Directed motion of electrons in gases under the action of photon flux - art. no. 0525122001Ingår i: PHYSICAL REVIEW A, ISSN 1050-2947, Vol. 6305, nr 5, s. 2512-+Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The phenomenon of directed motion of electrons and ions in gases under the action of ionizing radiation pressure is investigated. It is shown that for photon energies from the thresholds of atomic photoionization to several keV the photoionization process

  • 83.
    Andersson, Anna M
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi.
    Henningsson, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Siegbahn, Hans
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Jansson, Ulf
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi.
    Edström, Kristina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Strukturkemi.
    Electrochemically lithiated graphite characterised by photoelectron spectroscopy2003Ingår i: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 119-121, s. 522-527Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    X-ray photoelectron spectroscopy (XPS) has been used to study the depth profile of the solid–electrolyte interphase (SEI) formed on a graphite powder electrode in a Li-ion battery. The morphology of the SEI-layer, formed in a 1 M LiBF4 EC/DMC 2:1 solution, consists of a 900 Å porous layer of polymers (polyethylene oxide) and a 15–20 Å thin layer of Li2CO3 and LiBF4 reduction–decomposition products. Embedded LiF crystals as large as 0.2 μm were found in the polymer matrix. LiOH and Li2O are not major components on the surface but rather found as a consequence of sputter-related reactions. Monochromatised Al Kα XPS-analysis based on the calibration of Ar+ ion sputtering of model compounds combined with a depth profile analysis based on energy tuning of synchrotron XPS can describe the highly complex composition and morphology of the SEI-layer.

  • 84.
    Andersson, AS
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Kalska, B
    Eyob, P
    Aernout, D
    Haggstrom, L
    Thomas, JO
    Lithium insertion into rhombohedral Li3Fe2(PO4)(3)2001Ingår i: SOLID STATE IONICS, ISSN 0167-2738, Vol. 140, nr 1-2, s. 63-70Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The lithium insertion process has been studied in rhombohedral Li,Fe,(PO,), (NASICON-type structure) by electrochemical and Mossbauer spectroscopic methods. The form of the discharge curve and the effective discharge capacity is found to depend on the mod

  • 85.
    Andersson, AS
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Kalska, B
    Haggstrom, L
    Thomas, JO
    Lithium extraction/insertion in LiFePO4: an X-ray diffraction and Mossbauer spectroscopy study2000Ingår i: SOLID STATE IONICS, ISSN 0167-2738, Vol. 130, nr 1-2, s. 41-52Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The extraction and insertion of lithium in solid-state synthesized LiFePO4 has been followed by in situ X-ray diffraction and Mossbauer spectroscopy in 'coffee-bag' cells of type [Li-metal \ liq. el. \ LiFePO4] during the first cycle. Two-phase Rietveld r

  • 86.
    Andersson, AS
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen.
    Kalska, B
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Jonsson, P
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för materialvetenskap.
    Haggstrom, L
    Nordblad, P
    Tellgren, R
    Thomas, JO
    The magnetic structure and properties of rhombohedral Li3Fe2(PO4)(3)2000Ingår i: JOURNAL OF MATERIALS CHEMISTRY, ISSN 0959-9428, Vol. 10, nr 11, s. 2542-2547Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Magnetic susceptibility measurements indicate that rhombohedral Li3Fe2(PO4)(3), obtained by ion exchange of monoclinic Na3Fe2(PO4)(3), exhibits a paramagnetic to antiferromagnetic transition at T-N approximate to 27 K. Curie-Weiss-like behaviour is observ

  • 87.
    Andersson, AS
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen.
    Thomas, JO
    Fysiska sektionen, Fysiska institutionen.
    Kalska, B
    Haggstrom, L
    Thermal stability of LiFePO4-based cathodes2000Ingår i: ELECTROCHEMICAL AND SOLID STATE LETTERS, ISSN 1099-0062, Vol. 3, nr 2, s. 66-68Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The capacity and cyclability of solid-state synthesized LiFePO4-based laminate cells of type <Li \ liq. el. \ LiFePO4> have been studied at 23, 40, and 60 degrees C. Larger capacities were obtained for cells cycled at the elevated temperatures. No evidenc

  • 88.
    Andersson, Cecilia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen.
    Exploring the Magnetism of Ultra Thin 3d Transition Metal Films2006Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    In this thesis the magnetic and structural properties of ultra-thin 3d transition metals films have been investigated, in particular Fe, Ni and Co films. X-ray Magnetic Circular Dichroism (XMCD) has provided element specific spin (ms ) and orbital (ml ) moments per atom by utilizing the magneto optic sum-rules. Element specific hysteresis curves have been measured by means of X-ray Resonant Magnetic Scattering (XRMS), and the local crystallographic structure has been investigated using Extended X-ray Absorption Fine Structure (EXAFS).

    By performing XMCD on Fe/Ag(100) we observe a spin reorientation from in-plane to out-of-plane as the Fe thickness is lowered. At temperatures below 300K it occurs around 5-7 mono layers (ML) of Fe. While reorienting the magnetization out-of-plane the orbital moment increases with 125% but only a minor increase (5%) of the spin moment is observed. Extended X-ray Absorption Fine Structure (EXAFS) measurements indicate that films 6 ML and thicker have a bulk-like bcc structure. For the thin out-of-plane films, the local crystallographic structure is more complicated.

    The spin reorientation of the Au/Co/Au tri-layer system has been studied as a function of temperature, Co layer and Au cap thickness. An unexpected behavior of the orbital moment upon spin reorientation is found in these systems. An ex-situ prepared sample shows a smooth spin reorientation from an in-plane to an out-of-plane easy magnetization direction as the temperature is lowered from 300K to 200K. In-situ prepared samples have also been investigated and a novel phase diagram has been identified. The Au/Co interface has been explored during the Au capping by means of photoemission measurements.

    In the bi- and tri-layer system of Fe and Ni we have been able to manipulate the spin reorientation by varying the Fe and Ni thickness. A novel non-collinear interlayer exchange interaction for 3d ferro magnets in direct contact has been discovered for a set of samples. This exchange interaction is found to be strongly dependant on the preparation conditions.

    Delarbeten
    1. Structure and magnetism on in-situ ultrathin epitaxial films: XMCD and EXAFS on Fe/Ag(100)
    Öppna denna publikation i ny flik eller fönster >>Structure and magnetism on in-situ ultrathin epitaxial films: XMCD and EXAFS on Fe/Ag(100)
    Visa övriga...
    2003 (Engelska)Ingår i: Proceedings of the 7th International Conference on Nanometer-Scale Science and Technology and the 21st European Conference on Surface Science, 2003, Vol. 532-535, s. 76-81Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    We have made in situ investigations of epitaxial ultrathin Fe films on Ag(1 0 0). This system is known to exhibit a reorientation of the magnetization, dependent of Fe thickness and temperature. Our aim here is to correlate the local structure with the magnetic properties of this system. The X-ray absorption fine structure has been recorded in situ both in the near edge as well as in the extended X-ray absorption fine structure (EXAFS) range. Using X-ray magnetic circular dichroism we find that, below 300 K, films between 2 and 6 monolayers show an out-of-plane remanent magnetization whereas for thicker films the magnetization lies in-plane. By making use of the Fe L-edge EXAFS we obtain information on the local structure around the Fe atoms, such as the interatomic distances, the coordination number, and the mean square relative displacement of the first neighbor shells.

    Nationell ämneskategori
    Naturvetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-90370 (URN)10.1016/S0039-6028(03)00112-2 (DOI)
    Konferens
    7th International Conference on Nanometer-Scale Science and Technology and the 21st European Conference on Surface Science, 24-28 June, 2002, Malmo, Sweden
    Tillgänglig från: 2003-04-29 Skapad: 2003-04-29 Senast uppdaterad: 2013-09-18Bibliografiskt granskad
    2. Structure and magnetism for ultra-thin epitaxial Fe on Ag(100)
    Öppna denna publikation i ny flik eller fönster >>Structure and magnetism for ultra-thin epitaxial Fe on Ag(100)
    Visa övriga...
    2006 (Engelska)Ingår i: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 73, nr 13, s. 134423-Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    We have made in-situ investigations of ultrathin films of Fe grown on a Ag(100) single crystal. This system is known to exhibit a reorientation of the magnetization, dependent on both Fe thickness and temperature. X-ray absorption fine structure has been recorded for samples prepared in-situ, both in the near edge and in the extended x-ray absorption fine structure (EXAFS) region. Using x-ray magnetic circular dichroism we found that Fe films between 2–5 monolayers show an out-of-plane remanent magnetization. For thicker films the magnetization lies in-plane. By applying the magneto-optical sum rules we found an enhancement of the orbital moment (ml) for the out-of-plane phase, whereas the spin moment (ms) is unchanged. From the Fe L-edge EXAFS, we obtain information on the local crystallographic structure. A strong correlation between the local crystallographic structure and the magnetic properties is found for the Fe∕Ag(100) system. Variations in the nearest neighbor distance of ∼0.15 Å are observed when comparing 3 ML and 25 ML films. By comparison to simulations performed with the FEFF 8.10 code, we can identify a bcc structure for 6–25 ML Fe on Ag(100). For the 3 ML Fe film our simulations indicate strong deviations from any structure derived along the Bain path. We conclude that intermixing and distortion are important to describe the structure in this thickness range.

    Nationell ämneskategori
    Naturvetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-94434 (URN)10.1103/PhysRevB.73.134423 (DOI)
    Tillgänglig från: 2006-05-03 Skapad: 2006-05-03 Senast uppdaterad: 2017-12-14Bibliografiskt granskad
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    Öppna denna publikation i ny flik eller fönster >>On the temperature driven spin reorientation in Au/Co/Au
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    Manuskript (Övrigt vetenskapligt)
    Identifikatorer
    urn:nbn:se:uu:diva-94435 (URN)
    Tillgänglig från: 2006-05-03 Skapad: 2006-05-03 Senast uppdaterad: 2010-01-13Bibliografiskt granskad
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    Öppna denna publikation i ny flik eller fönster >>Spin reorientation in Au/Co: in-situ prepared ultra-thin films
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    Manuskript (Övrigt vetenskapligt)
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    urn:nbn:se:uu:diva-94436 (URN)
    Tillgänglig från: 2006-05-03 Skapad: 2006-05-03 Senast uppdaterad: 2010-01-13Bibliografiskt granskad
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    Öppna denna publikation i ny flik eller fönster >>Influence of ligand states on the relationship between orbital moment and magnetocrystalline anisotropy