Logo: to the web site of Uppsala University

uu.sePublications from Uppsala University
Change search
Link to record
Permanent link

Direct link
Alternative names
Publications (10 of 109) Show all publications
Fritze, S., Hahn, R., Aboulfadl, H., Johansson, F. O. .., Lindblad, R., Böör, K., . . . Thuvander, M. (2024). Elemental distribution and fracture properties of magnetron sputtered carbon supersaturated tungsten films. Surface & Coatings Technology, 477, Article ID 130326.
Open this publication in new window or tab >>Elemental distribution and fracture properties of magnetron sputtered carbon supersaturated tungsten films
Show others...
2024 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 477, article id 130326Article in journal (Refereed) Published
Abstract [en]

The combination of strength and toughness is a major driving force for alloy design of protective coatings, and nanocrystalline tungsten (W)-alloys have shown to be promising candidates for combining strength and toughness. Here we investigate the elemental distribution and the fracture toughness of carbon (C) alloyed W thin films prepared by non-reactive magnetron sputtering. W:C films with up to ~4 at.% C crystallize in a body-centered-cubic structure with a strong 〈hh0〉texture, and no additional carbide phases are observed in the diffraction pattern. Atom probe tomography and X-ray photoelectron spectroscopy confirmed the formation of such a supersaturated solid solution. The pure W film has a hardness ~13 GPa and the W:C films exhibit a peak hardness of ~24 GPa. In-situ micromechanical cantilever bending tests show that the fracture toughness decreases from ~4.5 MPa·m1/2 for the W film to ~3.1 MPa·m1/2 for W:C films. The results show that C can significantly enhance the hardness of W thin films while retaining a high fracture toughness.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
PVD, Fracture toughness, Atom probe tomography, XPS, Tungsten
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-521828 (URN)10.1016/j.surfcoat.2023.130326 (DOI)001149676000001 ()
Funder
Swedish Foundation for Strategic Research, RMA15-0048
Available from: 2024-01-29 Created: 2024-01-29 Last updated: 2024-02-15Bibliographically approved
Osinger, B., Donzel-Gargand, O., Fritze, S., Jansson, U. & Lewin, E. (2024). Structural and mechanical properties of magnetron sputtered (NbxMo1-x)C thin films. Vacuum, 224, Article ID 113146.
Open this publication in new window or tab >>Structural and mechanical properties of magnetron sputtered (NbxMo1-x)C thin films
Show others...
2024 (English)In: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 224, article id 113146Article in journal (Refereed) Published
Abstract [en]

While transition metal carbides (TMCs) exhibit favourable mechanical properties, alloying according to the valence electron concentration (VEC) has the potential to further enhance the properties of these hard but inherently brittle materials. This study investigates the influence of alloying on the microstructure and mechanical properties of (NbxMo1-x)C carbide films, including binary references and ternary compositions with varying metal ratios (x between 0.35 and 0.53). Furthermore, the influence of various substrate materials is studied by comparing films deposited on Al2O3, MgO and SiO2. All films exhibit a NaCl-type carbide structure and X-ray photoelectron spectroscopy revealed the presence of small amounts of an additional amorphous carbon (a-C) phase. Hardness values around 20 ± 2 GPa were obtained for the films on Al2O3 and MgO, whereas a reduced hardness of 11 ± 1 GPa was observed for the films on SiO2 which is attributed to larger crystallite size and more polycrystalline structure. Overall no clear trend as a function of composition can be noted, indicating that microstructure effects dominate the mechanical properties in this study overshadowing the effect of varying the metal content.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Magnetron sputtering, Ceramic coating, Transition metal carbides, Mechanical properties
National Category
Materials Chemistry
Research subject
Chemistry with specialization in Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-517298 (URN)10.1016/j.vacuum.2024.113146 (DOI)001218592400001 ()
Funder
Swedish Research Council, 2018-04834Swedish Research Council, 2017-00646_9Swedish Foundation for Strategic Research, RIF14-0053
Available from: 2024-01-09 Created: 2024-01-09 Last updated: 2024-05-31Bibliographically approved
Tunes, M. A., Fritze, S., Osinger, B., Willenshofer, P., Alvarado, A. M., Martinez, E., . . . El-Atwani, O. (2023). From high-entropy alloys to high-entropy ceramics: The radiation-resistant highly concentrated refractory carbide (CrNbTaTiW)C. Acta Materialia, 250, Article ID 118856.
Open this publication in new window or tab >>From high-entropy alloys to high-entropy ceramics: The radiation-resistant highly concentrated refractory carbide (CrNbTaTiW)C
Show others...
2023 (English)In: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 250, article id 118856Article in journal (Refereed) Published
Abstract [en]

High-entropy materials represent the state-of-the-art on the alloy design strategy for future applications in extreme environments. Recent data indicates that high-entropy alloys (HEAs) exhibit outstanding radiation resistance in face of existing diluted alloy counterparts due to suppressed damage formation and evolution. An extension of the HEA concept is presented in this paper towards the synthesis and characterization of novel high-entropy ceramics as emergent materials for application in environments where energetic particle irradiation is a major concern. A novel carbide within the quinary refractory system CrNbTaTiW has been synthesized using magnetron-sputtering. The material exhibited nanocrystalline grains, single-phase crystal structure and C content around 50 at.%. Heavy-ion irradiation with in-situ Transmission Electron Microscopy was used to assess the irradiation response of the new high-entropy carbide (HEC) at 573 K and a comparison with the HEA within the system is made. No displacement damage effects appear within the microstructures of both HEA and HEC up to a dose of 10 displacements-per-atom. Surprisingly, the HEC has not amorphized under the investigated conditions. Xe was implanted in both materials and bubbles nucleated, but smaller sizes compared with conventional nuclear materials shedding light they are potential candidates for use in nuclear energy.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
High-entropy ceramics, High-entropy alloys, Nanocrystalline materials, Radiation damage, Extreme environments
National Category
Materials Engineering
Identifiers
urn:nbn:se:uu:diva-499313 (URN)10.1016/j.actamat.2023.118856 (DOI)000958714700001 ()
Funder
EU, European Research Council, 757961Swedish Research Council, 2017-00646_9Swedish Research Council, 2019_00191Swedish Foundation for Strategic Research, RIF14-0053
Available from: 2023-03-27 Created: 2023-03-27 Last updated: 2024-01-11Bibliographically approved
Greczynski, G., Haasch, R. T., Hellgren, N., Lewin, E. & Hultman, L. (2023). X-ray photoelectron spectroscopy of thin films. NATURE REVIEWS METHODS PRIMERS, 3(1), Article ID 40.
Open this publication in new window or tab >>X-ray photoelectron spectroscopy of thin films
Show others...
2023 (English)In: NATURE REVIEWS METHODS PRIMERS, ISSN 2662-8449, Vol. 3, no 1, article id 40Article in journal (Refereed) Published
Abstract [en]

X-ray photoelectron spectroscopy (XPS) is a popular analytical technique in materials science as it can assess the surface chemistry of a broad range of samples. This Primer concerns best practice in XPS analysis, aimed at both entry-level and advanced users, with a focus on thin film samples synthesized under vacuum conditions. The high surface to volume ratio of thin films means that factors such as substrate choice and air exposure time are important for the final result. Essential concepts are introduced, such as binding energy, photoelectric effect, spectral referencing and chemical shift, as well as practical aspects including surface sensitivity, probing depth, energy resolution, sample handling and sputter etching. Correct procedures for experimental planning, instrument set-up, sample preparation, data acquisition, results analysis and presentation are reviewed in connection with physical principles and common applications. Typical problems, including charging, spectral overlap, sputter damage and binding energy referencing, are discussed along with possible solutions or workarounds. Finally, a workflow is presented for arriving at high-quality results. X-ray photoelectron spectroscopy (XPS) can be used to investigate chemical bonding and elemental composition. This Primer discusses how XPS can be used to characterize thin films, including key considerations for sample preparation, experimental set-up and data analysis.

Place, publisher, year, edition, pages
Springer Nature, 2023
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-505223 (URN)10.1038/s43586-023-00225-y (DOI)000995347100001 ()
Funder
Swedish Research Council, 2018-03957Swedish Energy Agency, 51201-1Knut and Alice Wallenberg Foundation, KAW2019.0290Vinnova, 2022-03071
Available from: 2023-06-27 Created: 2023-06-27 Last updated: 2023-06-27Bibliographically approved
Hanifpour, F., Canales, C. P., Fridriksson, E. G., Sveinbjörnsson, A., Tryggvason, T. K., Lewin, E., . . . Flosadóttir, H. D. (2022). Investigation into the mechanism of electrochemical nitrogen reduction reaction to ammonia using niobium oxynitride thin-film catalysts. Electrochimica Acta, 403, Article ID 139551.
Open this publication in new window or tab >>Investigation into the mechanism of electrochemical nitrogen reduction reaction to ammonia using niobium oxynitride thin-film catalysts
Show others...
2022 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 403, article id 139551Article in journal (Refereed) Published
Abstract [en]

Niobium oxynitride (NbOxNy) thin films with varying combined non-metal vs. metal stoichiometries ( x + y ) and N/O stoichiometric ratios (y/x) are investigated for their ability to catalyze the nitrogen re-duction reaction and ammonia synthesis at ambient conditions. Electrochemical impedance spectroscopy and ammonia measurements show stark differences both in nitrogen vs. argon media on each surface and on the surfaces in the series when the combined stoichiometry of N + O vs. Nb increases. Surface stability checks at fixed intervals during the experiments and surface characterization after the experiments us -ing X-ray diffraction reveal the least changes occurred to the surface with the highest N + O stoichiometry. Based on these observations, an ammonia synthesis mechanism is proposed. Isotope labeling experiments on the most promising surface of the series, however, show no sign of catalytically produced ammonia, possibly due to the lack of stability of the surface to endure through the ammonia production cycle. 

Place, publisher, year, edition, pages
ElsevierElsevier BV, 2022
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-470305 (URN)10.1016/j.electacta.2021.139551 (DOI)000784296000004 ()
Available from: 2022-03-22 Created: 2022-03-22 Last updated: 2024-01-15Bibliographically approved
Osinger, B., Mao, H., Fritze, S., Riekehr, L., Jansson, U. & Lewin, E. (2022). Investigation of the phase formation in magnetron sputtered hard multicomponent (HfNbTiVZr)C coatings. Materials & design, 221, Article ID 111002.
Open this publication in new window or tab >>Investigation of the phase formation in magnetron sputtered hard multicomponent (HfNbTiVZr)C coatings
Show others...
2022 (English)In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 221, article id 111002Article in journal (Refereed) Published
Abstract [en]

Multicomponent carbides have gained interest especially for ultra-high temperature applications, due to their ceramic hardness, good oxidation resistance and enhanced strength. In this study the phase forma-tion, stability and mechanical properties of (HfNbTiVZr)C multicomponent carbide coatings were inves-tigated. Phase stability was predicted by the CALPHAD (CALculation of PHAse Diagrams) methods. This revealed that the multicomponent solid solution phase is only stable at elevated temperatures, namely above 2400 degrees C. At lower temperatures a phase mixture was predicted, with a particular tendency for V to segregate. Magnetron sputtered thin films deposited at 300 degrees C exhibited a single NaCl-type multicom-ponent carbide phase, which attributes to the kinetic stabilisation of simple structures during thin film growth. Films deposited at 700 degrees C, or exposed to UHV annealing at 1000 degrees C, however, revealed the decom-position of the single-phase multicomponent carbide by partial elemental segregation and formation of additional phases. Thus, confirming the CALPHAD predictions. These results underscore the importance of explicitly considering temperature when discussing the stability of multicomponent carbide materials, as well as the applicability of CALPHAD methods for predicting phase formation and driving forces in these materials. The latter being crucial for designing materials, such as carbides, that are used in appli-cations at elevated temperatures.

Place, publisher, year, edition, pages
ElsevierElsevier BV, 2022
Keywords
High entropy ceramics, Multi -principal element carbide, Multicomponent carbide, Physical vapour deposition (PVD), CALPHAD
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-482676 (URN)10.1016/j.matdes.2022.111002 (DOI)000839257000004 ()
Funder
Swedish Research Council, 2018-04834Swedish Research CouncilSwedish Research Council, 2017-00646_9Swedish Foundation for Strategic Research, RIF14-0053
Available from: 2022-09-07 Created: 2022-09-07 Last updated: 2024-01-15Bibliographically approved
Lewin, E. (2022). Oordning ger nya material. Allkemi (1), 10-11
Open this publication in new window or tab >>Oordning ger nya material
2022 (Swedish)In: Allkemi, ISSN 2003-6817, no 1, p. 10-11Article in journal (Other (popular science, discussion, etc.)) Published
Abstract [sv]

Intresset är stort för de nya högentropilegeringarna som består av fem eller fler grundämnen i en kombination av ordning oordning. Nya egenskaper har observerats – men väntar ännu på sin förklaring.

Place, publisher, year, edition, pages
IKEM – Innovations- och kemiindustrierna i Sverige, 2022
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-470188 (URN)
Note

Populärvetenskaplig artikel riktad mot skolungdom.

Available from: 2022-03-21 Created: 2022-03-21 Last updated: 2022-03-29Bibliographically approved
Lewin, E. (2022). Oordning skapar nya material. Kemisk tidskrift (1), 20-23
Open this publication in new window or tab >>Oordning skapar nya material
2022 (Swedish)In: Kemisk tidskrift, ISSN 2003-2722, no 1, p. 20-23Article in journal (Other (popular science, discussion, etc.)) Published
Abstract [sv]

Förhoppningarna är stora på de nya, heta HÖGENTROPIMATERIALEN – som består av fem eller fler grundämnen. De har egenskaper som gör dem intressanta för exempelvis omvandling, lagring och transport av energi.

Place, publisher, year, edition, pages
Svenska Kemisamfundet, 2022
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-470187 (URN)
Note

Populärvetenskaplig artikel riktad mot andra kemister.

Available from: 2022-03-21 Created: 2022-03-21 Last updated: 2022-03-29Bibliographically approved
Hanifpour, F., Canales, C. P., Fridriksson, E. G., Sveinbjörnsson, A., Tryggvason, T. K., Yang, J., . . . Skulason, E. (2022). Operando quantification of ammonia produced from computationally-derived transition metal nitride electro-catalysts. Journal of Catalysis, 413, 956-967
Open this publication in new window or tab >>Operando quantification of ammonia produced from computationally-derived transition metal nitride electro-catalysts
Show others...
2022 (English)In: Journal of Catalysis, ISSN 0021-9517, E-ISSN 1090-2694, Vol. 413, p. 956-967Article in journal (Refereed) Published
Abstract [en]

Electrochemical reduction of dinitrogen to ammonia is investigated in a micro-reactor flow-cell using thin films of VN, CrN, NbN and ZrN. Chronoamperometry loops are used for ammonia production analysis. Operando ammonia quantification is accomplished in a flow injection analyzer. Results show the effect of presence/absence of N-2(g) within both the electrochemical characterization and ammonia production for ZrN. However, no ammonia is detected from studies on CrN. VN and NbN are inactivated upon reacting their N atoms of the surface top layer(s). Results obtained from ammonia measurements, electrochemical impedance spectroscopy analysis, surface stability checks, and surface characterization using X-ray reflectivity, reveal certain trends indicating catalytic behavior for ZrN. However, the concentration of produced ammonia is below the detection limit of the methods devised to analyze the samples from isotope labeling experiments. The onset of ammonia production on ZrN appears to be in close agreement with that predicted previously by computational studies.

Place, publisher, year, edition, pages
Elsevier, 2022
Keywords
Nitrogen reduction reaction, Ammonia electrosynthesis, Transition metal nitride thin films, Ambient condition, Aqueous electrolyte solution
National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-489999 (URN)10.1016/j.jcat.2022.07.030 (DOI)000885461000008 ()
Available from: 2022-12-07 Created: 2022-12-07 Last updated: 2022-12-07Bibliographically approved
Mukhamedov, B., Fritze, S., Ottosson, M., Osinger, B., Lewin, E., Alling, B., . . . Abrikosov, I. (2022). Tetragonal distortion in magnetron sputtered bcc-W films with supersaturated carbon. Materials & design, 214, Article ID 110422.
Open this publication in new window or tab >>Tetragonal distortion in magnetron sputtered bcc-W films with supersaturated carbon
Show others...
2022 (English)In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 214, article id 110422Article in journal (Refereed) Published
Abstract [en]

Carbon has a low solid solubility in bcc tungsten at equilibrium. However, metastable supersaturated solid solutions can be synthesized with magnetron sputtering. Here, we present a systematic study on the phase stability and mechanical properties of such supersaturated W–C solid solutions. Θ–2θ scans show a split of the 200/020 and the 002 peaks for supersaturated films which is explained by a tetragonal distortion of the bcc structure. This split increases with increasing C content and is maximized at 4 at.% C, where we observe an a/b axis of 3.15–3.16 Å and a c-axis of 3.21–3.22 Å. We performed first-principles calculations of lattice parameters, mixing enthalpies, elastic constants and polycrystalline elastic moduli for cubic and tetragonal W–C solid solutions. Calculations show that tetragonal structure is more stable than the bcc supersaturated solid solution and the calculated lattice parameters and Young’s moduli follow the same trends as the experimental ones as a function of C concentration. The results suggest that supersaturated films with lattice distortion can be used as a design approach to improve the properties of transition metal films with a bcc structure.

Place, publisher, year, edition, pages
ElsevierElsevier BV, 2022
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-470304 (URN)10.1016/j.matdes.2022.110422 (DOI)000761243900006 ()
Funder
Swedish Foundation for Strategic Research , 2019-05403Swedish Foundation for Strategic Research , FFL 15-0290Linköpings universitetKnut and Alice Wallenberg Foundation, KAW-2018.0194Swedish Research Council, 2009 00971Swedish Research Council, 2018-04834
Available from: 2022-03-22 Created: 2022-03-22 Last updated: 2024-01-15Bibliographically approved
Projects
Anmälan om utnyttjande av återvändarbidrag för beviljade postdoktorsstipendier inom medicin eller natur- och teknikvetenskap [2013-00069_VR]; Uppsala University
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-8617-4834

Search in DiVA

Show all publications