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Lindahl, E., Ottosson, M. & Carlsson, J.-O. (2018). Doping of metastable Cu3N at different Ni concentrations: Growth, crystallographic sites and resistivity. Thin Solid Films, 647, 1-8
Open this publication in new window or tab >>Doping of metastable Cu3N at different Ni concentrations: Growth, crystallographic sites and resistivity
2018 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 647, p. 1-8Article in journal (Refereed) Published
Abstract [en]

Copper nitride, Cu3N, is a metastable material whose properties can be changed considerably by doping with metals which opens for a variety of applications in several areas (sensors, electrical connects, batteries, memories, etc.). The present work is a systematic study in the system Cu-Ni-N of preferences regarding occupation of interstitial and substitutional crystallographic sites in the Cu3N structure as the metal dopant level increases and how the occupation influences growth behavior, texture, microstructure and resistivity. Ni doped Cu3N films of different chemical composition were grown by a gas-pulsed Chemical Vapor Deposition technique. The occupation of the different crystallographic sites of the Cu3N by the Ni atoms was obtained from analysis of X-ray diffraction data. At low Ni content, less than about 21% in metal content, Ni replaced the Cu atoms in the structure. In the intermediate Ni metal content range from about 21 to 40% the vacant centre position became available. After filling the centre position, substitution of Cu for Ni occurred up to a Ni content of about 80% (Cu0.8Ni3.2N) which is the solid solubility limit of Ni in Cu3N. The film resistivity decreased rapidly by adding nickel to the Cu3N structure from about 10(9)mu Omega.cm without any Ni doping to about 100 mu Omega.cm with 80% Ni in the metal content. After filling the centre position the change in resistivity when Cu atoms were substituted for Ni was very small. Finally, the growth mechanism, texture and microstructure changed significantly with the uptake of Ni atoms in the structure.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE SA, 2018
Keywords
Copper nitride, Metal doping, Solid solubility, Cell parameters, Resistivity, Growth mechanism, Microstructure
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-341567 (URN)10.1016/j.tsf.2017.12.010 (DOI)000419649200001 ()
Funder
Swedish Research Council, 7048301
Available from: 2018-02-12 Created: 2018-02-12 Last updated: 2018-02-12Bibliographically approved
Chulapakorn, T., Sychugov, I., Ottosson, M., Primetzhofer, D., Moro, M., Linnros, J. & Hallén, A. (2018). Luminescence of Silicon Nanoparticles from Oxygen Implanted Silicon. Materials Science in Semiconductor Processing, 86, 18-22
Open this publication in new window or tab >>Luminescence of Silicon Nanoparticles from Oxygen Implanted Silicon
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2018 (English)In: Materials Science in Semiconductor Processing, ISSN 1369-8001, E-ISSN 1873-4081, Vol. 86, p. 18-22Article in journal (Refereed) Published
Abstract [en]

Oxygen with a kinetic energy of 20 keV is implanted in a silicon wafer (100) at different fluences, followed by post-implantation thermal annealing (PIA) performed at temperatures ranging from 1000 to 1200 degrees C, in order to form luminescent silicon nanoparticles (SiNPs) and also to reduce the damage induced by the implantation. As a result of this procedure, a surface SiOx layer (with 0 < x < 2) with embedded crystalline Si nanoparticles has been created. The samples yield similar luminescence in terms of peak wavelength, lifetime, and absorption as recorded from SiNPs obtained by the more conventional method of implanting silicon into silicon dioxide. The oxygen implantation profile is characterized by elastic recoil detection (ERD) technique to obtain the excess concentration of Si in a presumed SiO2 environment. The physical structure of the implanted Si wafer is examined by grazing incidence X-ray diffraction (GIXRD). Photoluminescence (PL) techniques, including PL spectroscopy, time-resolved PL (TRPL), and photoluminescence excitation (PLE) spectroscopy are carried out in order to identify the PL origin. The results show that luminescent SiNPs are formed in a Si sample implanted by oxygen with a fluence of 2 x 10(17) atoms cm(-2) and PIA at 1000 degrees C. These SiNPs have a broad size range of 6-24 nm, as evaluated from the GIXRD result. Samples implanted at a lower fluence and/or annealed at higher temperature show only weak defect-related PL. With further optimization of the SiNP luminescence, the method may offer a simple route for integration of luminescent Si in mainstream semiconductor fabrication.

National Category
Condensed Matter Physics
Research subject
Physics
Identifiers
urn:nbn:se:uu:diva-346929 (URN)10.1016/j.mssp.2018.06.004 (DOI)000439119400003 ()
Funder
Swedish Research Council, 821-2012-5144Swedish Research Council, 2017-00646_9Swedish Foundation for Strategic Research
Available from: 2018-03-22 Created: 2018-03-22 Last updated: 2018-09-26Bibliographically approved
Farkas, B., Heszler, P., Budai, J., Oszko, A., Ottosson, M. & Geretovszky, Z. (2018). Optical, compositional and structural properties of pulsed laser deposited nitrogen-doped Titanium-dioxide. Applied Surface Science, 433, 149-154
Open this publication in new window or tab >>Optical, compositional and structural properties of pulsed laser deposited nitrogen-doped Titanium-dioxide
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2018 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 433, p. 149-154Article in journal (Refereed) Published
Abstract [en]

N-doped TiO2 thin films were prepared using pulsed laser deposition by ablating metallic Ti target with pulses of 248 nm wavelength, at 330 °C substrate temperature in reactive atmospheres of N2/O2 gas mixtures. These films were characterized by spectroscopic ellipsometry, X-ray photoelectron spectroscopy and X-ray diffraction. Optical properties are presented as a function of the N2 content in the processing gas mixture and correlated to nitrogen incorporation into the deposited layers. The optical band gap values decreased with increasing N concentration in the films, while a monotonically increasing tendency and a maximum can be observed in case of extinction coefficient and refractive index, respectively. It is also shown that the amount of substitutional N can be increased up to 7.7 at.%, but the higher dopant concentration inhibits the crystallization of the samples.

Keywords
TiONx, Photocatalytic material, PLD, Ellipsometry, Chemical composition, Structural property
National Category
Materials Chemistry Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:uu:diva-351086 (URN)10.1016/j.apsusc.2017.09.181 (DOI)000418883800019 ()
Available from: 2018-05-18 Created: 2018-05-18 Last updated: 2018-05-18Bibliographically approved
Ottosson, M., Boman, M., Berastegui, P., Andersson, Y., Hahlin, M., Korvela, M. & Berger, R. (2018). Response to the comments by P. Szakalos, T. angstrom kermark and C. Leygraf on the paper "Copper in ultrapure water, a scientific issue under debate" [Letter to the editor]. Corrosion Science, 142, 308-311
Open this publication in new window or tab >>Response to the comments by P. Szakalos, T. angstrom kermark and C. Leygraf on the paper "Copper in ultrapure water, a scientific issue under debate"
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2018 (English)In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 142, p. 308-311Article in journal, Letter (Other academic) Published
Keywords
Copper, XPS, AES, Oxidation
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:uu:diva-366387 (URN)10.1016/j.corsci.2018.02.003 (DOI)000444933400030 ()
Available from: 2018-11-21 Created: 2018-11-21 Last updated: 2018-11-21Bibliographically approved
Ottosson, M., Boman, M., Berastegui, P., Andersson, Y., Hedlund, M., Korvela, M. & Berger, R. (2017). Copper in ultrapure water, a scientific issue under debate. Corrosion Science, 122, 53-60
Open this publication in new window or tab >>Copper in ultrapure water, a scientific issue under debate
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2017 (English)In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 122, p. 53-60Article in journal (Refereed) Published
Abstract [en]

The corrosion properties of copper in ultrapure water have been studied experimentally by submerging copper samples (99.9999%) in pure water for up to 29 months. The surface was first electropolished at ambient temperature, then exposed to hydrogen gas treatment at 300-400 degrees C, thereby reducing the bulk hydrogen content to 0.03 ppm. These copper samples, the water and the glassware were all then subjected to precise chemical analysis. Great care was taken to avoid contamination. After exposure, only similar to 6 mu g/L copper had accumulated in the water phase. Electron spectroscopy could not detect Cu2O or any other oxidation products containing copper.

Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD, 2017
Keywords
Copper, XPS, AES, Oxidation
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-330714 (URN)10.1016/j.corsci.2017.03.014 (DOI)000404490600006 ()
Available from: 2017-10-09 Created: 2017-10-09 Last updated: 2017-12-28Bibliographically approved
Mao, F., Taher, M., Kryshtal, O., Kruk, A., Czyrska-Filemonowicz, A., Ottosson, M., . . . Jansson, U. (2016). Combinatorial Study of Gradient Ag-Al Thin Films: Microstructure, Phase Formation, Mechanical and Electrical Properties. ACS Applied Materials and Interfaces, 8(44), 30635-30643
Open this publication in new window or tab >>Combinatorial Study of Gradient Ag-Al Thin Films: Microstructure, Phase Formation, Mechanical and Electrical Properties
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2016 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 8, no 44, p. 30635-30643Article in journal (Refereed) Published
Abstract [en]

A combinatorial approach is applied to rapidly deposit and screen Ag-Al thin films-to evaluate the mechanical, tribological, and electrical properties as a function of chemical composition. Ag-Al thin films with large continuous composition gradients (6-60 atom % Al) were deposited by a custom-designed combinatorial magnetron sputtering system. X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning and transmission electron microscopy (SEM and TEM), X-ray photoelectron spectroscopy (XPS), nanoindentation, and four-point electrical resistance screening were employed to characterize the chemical composition, structure, and physical properties of the films in a time-efficient way. For low Al contents (<13 atom %), a highly (111)-textured fcc phase was formed. At higher Al contents, a (002)-textured hcp solid solution phase was formed followed by a fcc phase in the most At-rich regions. No indication of a mu phase was observed. The Ag-Al films with fcc-Ag matrix is prone to adhesive material transfer leading to a high friction coefficient (>1) and adhesive wear, similar to the behavior of pure Ag. In contrast, the hexagonal solid solution phase (from ca. 15 atom %Al) exhibited dramatically reduced friction coefficients (about 15% of that of the fcc phase) and dramatically reduced adhesive wear when tested against the pure Ag counter surface. The increase in contact resistance of the Ag Al films is limited to only 50% higher than a pure Ag reference sample at the low friction and low wear region (19-27 atom %). This suggests that a hcp Ag Al alloy can have a potential use in sliding electrical contact applications and in the future will replace pure Ag in specific electromechanical applications.

Keywords
Ag-Al alloy, combinatorial approach, low friction, adhesive wear, hexagonal phase, electrical contact
National Category
Materials Chemistry Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-310756 (URN)10.1021/acsami.6b10659 (DOI)000387737200089 ()
Funder
SweGRIDS - Swedish Centre for Smart Grids and Energy Storage, 38432-1Knut and Alice Wallenberg FoundationSwedish Foundation for Strategic Research
Available from: 2016-12-20 Created: 2016-12-19 Last updated: 2017-11-29Bibliographically approved
Jacobsson, T. J., Schwan, L. J., Ottosson, M., Hagfeldt, A. & Edvinsson, T. (2015). Determination of Thermal Expansion Coefficients and Locating the Temperature-Induced Phase Transition in Methylammonium Lead Perovskites Using X-ray Diffraction. Inorganic Chemistry, 54(22), 10678-10685
Open this publication in new window or tab >>Determination of Thermal Expansion Coefficients and Locating the Temperature-Induced Phase Transition in Methylammonium Lead Perovskites Using X-ray Diffraction
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2015 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 54, no 22, p. 10678-10685Article in journal (Refereed) Published
Abstract [en]

Lead halogen perovskites, and particularly methylammonium lead iodine, CH3NH3PbI3, have recently attracted considerable interest as alternative solar cell materials, and record solar cell efficiencies have now surpassed 20%. Concerns have, however, been raised about the thermal stability of methylammonium lead iodine, and a phase transformation from a tetragonal to a cubic phase has been reported at elevated temperature. Here, this phase transition has been investigated in detail using temperature-dependent X-ray diffraction measurements. The phase transformation is pinpointed to 54 degrees C, which is well within the normal operating range of a typical solar cell. The cell parameters were extracted as a function of the temperature, from which the thermal expansion coefficient was calculated. The latter was found to be rather high (alpha(v) = 1.57 X 10(-4) K-1) for both the tetragonal and cubic phases. This is 6 times higher than the thermal expansion coefficient for soda lime glass and CIGS and 11 times larger than that of CdTe. This could potentially be of importance for the mechanical stability of perovskite solar cells in the temperature cycling experienced under normal day night operation. The experimental knowledge of the thermal expansion coefficients and precise determination of the cell parameters can potentially also be valuable while conducting density functional theory simulations on these systems in order to deliver more accurate band structure calculations.

National Category
Physical Chemistry Inorganic Chemistry Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-271026 (URN)10.1021/acs.inorgchem.5b01481 (DOI)000364981300022 ()26457861 (PubMedID)
Available from: 2016-01-05 Created: 2016-01-05 Last updated: 2017-12-01Bibliographically approved
Wikberg, J. M., Razdolski, I., Kirilyuk, A., Rasing, T., Sadowski, J., Ottosson, M., . . . Svedlindh, P. (2015). Evolving magnetization dynamics in Mn3-xGa. In: Bigot, JY; Hubner, W; Rasing, T; Chantrell, R (Ed.), Ultrafast Magnetism I: . Paper presented at Ultrafast Magnetization Conference, OCT 28-NOV 01, 2013, Strasbourg, FRANCE (pp. 23-25).
Open this publication in new window or tab >>Evolving magnetization dynamics in Mn3-xGa
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2015 (English)In: Ultrafast Magnetism I / [ed] Bigot, JY; Hubner, W; Rasing, T; Chantrell, R, 2015, p. 23-25Conference paper, Published paper (Refereed)
Series
Springer Proceedings in Physics, ISSN 0930-8989 ; 159
National Category
Condensed Matter Physics Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-309670 (URN)10.1007/978-3-319-07743-7_8 (DOI)000349745400008 ()9783319077437 (ISBN)9783319077420 (ISBN)
Conference
Ultrafast Magnetization Conference, OCT 28-NOV 01, 2013, Strasbourg, FRANCE
Available from: 2016-12-06 Created: 2016-12-06 Last updated: 2016-12-14Bibliographically approved
Lagerqvist, U., Svedlindh, P., Gunnarsson, K., Lu, J., Hultman, L., Ottosson, M. & Pohl, A. (2015). Morphology effects on exchange anisotropy in Co-CoO nanocomposite films. Thin Solid Films, 576, 11-18
Open this publication in new window or tab >>Morphology effects on exchange anisotropy in Co-CoO nanocomposite films
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2015 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 576, p. 11-18Article in journal (Refereed) Published
Abstract [en]

Co-CoO composite films were prepared by solution chemical technique using amine-modified nitrates and acetates in methanol. We study how particle size and porosity can be tuned through the synthesis parameters and how this influences the magnetic properties. Phase content and microstructure were characterised with grazing incidence X-ray diffraction and electron microscopy, and the magnetic properties were studied by magnetometry and magnetic force microscopy. Composite films were obtained by heating spin-coated films in Ar followed by oxidation in air at room temperature, and the porosity and particle size of the films were controlled by gas flow and heating rate. The synthesis yielded dense films with a random distribution of metal and oxide nanoparticles, and layered films with porosity and sintered primary particles. Exchange anisotropy, revealed as a shift towards negative fields of the magnetic hysteresis curve, was found in all films. The films with a random distribution of metal and oxide nanoparticles displayed a significantly larger coercivity and exchange anisotropy field compared to the films with a layered structure, whereas the layered films displayed a larger nominal saturation magnetisation. The magnitude of the coercivity decreased with increasing Co grain size, whereas increased porosity caused an increased tilt of the magnetic hysteresis curve. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license

Keywords
Co-CoO composite, Thin film, Solution chemical synthesis, Morphology effect, Magnetism, Exchange anisotropy, Magnetic stray field
National Category
Physical Sciences Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-246807 (URN)10.1016/j.tsf.2014.11.064 (DOI)000349373300002 ()
Available from: 2015-03-16 Created: 2015-03-10 Last updated: 2017-12-04Bibliographically approved
Boman, M., Berger, R., Andersson, Y., Hahlin, M., Björefors, F., Gustafsson, T. & Ottosson, M. (2014). Corrosion of copper in water free from molecular oxygen. Corrosion Engineering, Science and Technology, 49(6), 431-434
Open this publication in new window or tab >>Corrosion of copper in water free from molecular oxygen
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2014 (English)In: Corrosion Engineering, Science and Technology, ISSN 1478-422X, E-ISSN 1743-2782, Vol. 49, no 6, p. 431-434Article in journal (Refereed) Published
Abstract [en]

The possibility of copper reacting with O-2-free water has been investigated by analysis of primary corrosion products, as well as by monitoring gas pressure change by time, in long term experiments for up to 6 months in a glove box environment. We establish hydrogen production, but being of the same magnitude irrespective whether copper is present or not. Although low, the hydrogen production rate is considerably larger than what would directly correspond to the amount of analysed copper oxidation products. Our analyses encompass the changes to the surface cleaned copper (99.9999%), the water phase and the Duran glass in contact with the water (ppt quality). We have used very sensitive methods (XPS, AES, ICP-MS, XRF) while keeping contamination risks to a minimum. We conclude that the oxidation rate of copper is very low, yielding only parts of a monolayer of Cu2O after 6 months of exposure at 50 degrees C together with an accompanying very low concentration of copper species (4-5 mu g L-1) in the water phase.

Keywords
Copper corrosion, Pure water, Nuclear waste canister
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-241537 (URN)10.1179/1743278214Y.0000000199 (DOI)000346129000007 ()
Available from: 2015-01-13 Created: 2015-01-13 Last updated: 2017-12-05Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-0013-380x

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