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BETA
Alling, Björn
Alternative names
Publications (10 of 87) Show all publications
Landälv, L., Carlström, C.-F., Lu, J., Primetzhofer, D., Jöesaar, M. J., Ahlgren, M., . . . Eklund, P. (2019). Phase composition and transformations in magnetron-sputtered (Al,V)2O3 coatings. Thin Solid Films
Open this publication in new window or tab >>Phase composition and transformations in magnetron-sputtered (Al,V)2O3 coatings
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2019 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731Article in journal (Refereed) In press
Abstract [en]

Coatings of (Al1-xVx)2O3, with x ranging from 0 to 1, were deposited by pulsed DC reactive sputter deposition on Si(100) at a temperature of 550 °C. XRD showed three different crystal structures depending on V-metal fraction in the coating: α-V2O3 rhombohedral structure for 100 at.% V, a defect spinel structure for the intermediate region, 63–42 at.% V. At lower V-content, 18 and 7 at.%, a gamma-alumina-like solid solution was observed, shifted to larger d-spacing compared to pure γ-Al2O3. The microstructure changes from large columnar faceted grains for α-V2O3 to smaller equiaxed grains when lowering the vanadium content towards pure γ-Al2O3. Annealing in air resulted in formation of V2O5 crystals on the surface of the coating after annealing to 500 °C for 42 at.% V and 700 °C for 18 at.% V metal fraction respectively. The highest thermal stability was shown for pure γ-Al2O3-coating, which transformed to α-Al2O3 after annealing to 1100 °C. Highest hardness was observed for the Al-rich oxides, ~24 GPa. The latter decreased with increasing V-content, larger than 7 at.% V metal fraction. The measured hardness after annealing in air decreased in conjunction with the onset of further oxidation of the coatings.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Aluminum vanadium oxide Pulsed DC magnetron sputtering Annealing V2O5 AlVO4 AlVO3
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-159749 (URN)10.1016/j.tsf.2019.06.019 (DOI)
Available from: 2019-08-20 Created: 2019-08-20 Last updated: 2019-09-06Bibliographically approved
Ektarawong, A., Feng, Y. P. & Alling, B. (2019). Phase stability of two-dimensional monolayer As1-xPx solid solutions revealed by a first-principles cluster expansion. PHYSICAL REVIEW MATERIALS, 3(5), Article ID 054005.
Open this publication in new window or tab >>Phase stability of two-dimensional monolayer As1-xPx solid solutions revealed by a first-principles cluster expansion
2019 (English)In: PHYSICAL REVIEW MATERIALS, ISSN 2475-9953, Vol. 3, no 5, article id 054005Article in journal (Refereed) Published
Abstract [en]

The phase stability of two-dimensional monolayer As1-xPx solid solutions, exhibiting the puckered (alpha phase) and buckled (beta phase) structures are investigated using a first-principles cluster-expansion method. Canonical Monte Carlo simulations, together with harmonic approximation, are performed to capture the influences of thermally induced configurational disorder and lattice vibrations on the phase stability of monolayer As1-xPx. We first demonstrate that, as the temperature approaches 0 K, the monolayer As1-xPx displays a tendency toward phase separation into its constituent elemental phases, and thus no stable ordered structures of As1-xPx, both alpha and beta phases, are predicted to be thermodynamically stable. We further reveal with the inclusion of the lattice vibrational contributions that beta-As1-xPx is thermodynamically favored over alpha-As1-xPx, across the entire composition range even at 0 K and increasingly so at higher temperature, and a continuous series of disordered solid solution of beta-As1-xPx, where 0 amp;lt;= x amp;lt;= 1, is predicted at the temperature above 550 K. These findings not only indicate that the ordered structures of monolayer alpha-As1-xPx, and beta-As1-xPx, frequently studied in the literature, may not exist in nature, but also presumably suggest that monolayer alpha-As1-xPx is metastable with respect to monolayer beta-As1-xPx.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2019
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:liu:diva-158567 (URN)10.1103/PhysRevMaterials.3.054005 (DOI)000470902100002 ()
Note

Funding Agencies|Swedish Research Council (VR) [2014-6336]; Marie Sklodowska Curie Actions, Cofund, Project [INCA 600398]; Swedish Foundation for Strategic Research (SSF) through the Future Research Leaders 6 programme; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; Kungl. Ingenjorsvetenskapsakademiens Hans Werthen-Fond

Available from: 2019-07-03 Created: 2019-07-03 Last updated: 2019-07-03
Gambino, D. & Alling, B. (2018). Lattice relaxations in disordered Fe-based materials in the paramagnetic state from first principles. Physical Review B, 98(6), Article ID 064105.
Open this publication in new window or tab >>Lattice relaxations in disordered Fe-based materials in the paramagnetic state from first principles
2018 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 98, no 6, article id 064105Article in journal (Refereed) Published
Abstract [en]

The first-principles calculation of many material properties, in particular related to defects and disorder, starts with the relaxation of the atomic positions of the system under investigation. This procedure is routine for nonmagnetic and magnetically ordered materials. However, when it comes to magnetically disordered systems, in particular the paramagnetic phase of magnetic materials, it is not clear how the relaxation procedure should be performed or which geometry should be used. Here we propose a method for the structural relaxation of magnetic materials in the paramagnetic regime, in an adiabatic fast-magnetism approximation within the disordered local moment (DLM) picture in the framework of density functional theory. The method is straightforward to implement using any ab initio code that allows for structural relaxations. We illustrate the importance of considering the disordered magnetic state during lattice relaxations by calculating formation energies and geometries for an Fe vacancy and C insterstitial atom in body-centered cubic (bcc) Fe as well as bcc Fe1-xCrx random alloys in the paramagnetic state. In the vacancy case, the nearest neighbors to the vacancy relax toward the vacancy of 0.14 angstrom (-5% of the ideal bcc nearest-neighbor distance), which is twice as large as the relaxation in the ferromagnetic case. The vacancy formation energy calculated in the DLM state on these positions is 1.60 eV, which corresponds to a reduction of about 0.1 eV compared to the formation energy calculated using DLM but on ferromagnetic-relaxed positions. The carbon interstitial formation energy is found to be 0.41 eV when the DLM relaxed positions are used, as compared to 0.59 eV when the FM-relaxed positions are employed. For bcc Fe0.5Cr0.5 alloys, the mixing enthalpy is reduced by 5 meV/atom, or about 10%, when the DLM state relaxation is considered, as compared to positions relaxed in the ferromagnetic state.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2018
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-151199 (URN)10.1103/PhysRevB.98.064105 (DOI)000443139600004 ()
Note

Funding Agencies|Swedish Research Council (VR) [2014-6336]; Marie Sklodowska Curie Actions, Cofund [INCA 600398]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFOMatLiU) [2009 00971]; Swedish Foundation for Strategic Research

Available from: 2018-09-13 Created: 2018-09-13 Last updated: 2019-05-14
Ektarawong, A. & Alling, B. (2018). Stability of SnSe1-xSx solid solutions revealed by first-principles cluster expansion. Journal of Physics: Condensed Matter, 30(29), Article ID 29LT01.
Open this publication in new window or tab >>Stability of SnSe1-xSx solid solutions revealed by first-principles cluster expansion
2018 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 30, no 29, article id 29LT01Article in journal (Refereed) Published
Abstract [en]

The configurational thermodynamics of a pseudo-binary alloy SnSe1-xSx in the Pnma phase is studied using first-principles cluster-expansion method in combination with canonical Monte Carlo simulations. We find that, despite the alloy having a tendency toward a phase decomposition into SnSe and SnS at 0 K, the two constituent binaries readily mix with each other to form random SnSe1-xSx solid solutions even at a temperature below room temperature. The obtained isostructural phase diagram of SnSe1-xSx reveals that the alloy is thermodynamically stable as a single-phase random solid solution over a whole composition range above 200 K. These findings provide a fundamental understanding on the alloying behavior of SnSe1-xSx and bring clarity to the debated clustering tendency in this alloy system.

Place, publisher, year, edition, pages
IOP PUBLISHING LTD, 2018
Keywords
configurational thermodynamics; first-principles approach; cluster-expansion formalism; SnSe1-xSx alloy
National Category
Physical Chemistry
Identifiers
urn:nbn:se:liu:diva-149681 (URN)10.1088/1361-648X/aacb9c (DOI)000436395200001 ()29889052 (PubMedID)
Note

Funding Agencies|Swedish Research Council (VR) [2014-6336]; Marie Sklodowska Curie Actions, Cofund [INCA 600398]; Swedish Foundation for Strategic Research (SSF); Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]

Available from: 2018-07-25 Created: 2018-07-25 Last updated: 2018-08-14
Tholander, C., Birch, J., Tasnádi, F., Hultman, L., Palisaitis, J., Persson, P. O., . . . Zukauskaitè, A. (2016). Ab initio calculations and experimental study of piezoelectric YxIn1-xN thin films deposited using reactive magnetron sputter epitaxy. Acta Materialia, 105, 199-206
Open this publication in new window or tab >>Ab initio calculations and experimental study of piezoelectric YxIn1-xN thin films deposited using reactive magnetron sputter epitaxy
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2016 (English)In: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 105, p. 199-206Article in journal (Refereed) Published
Abstract [en]

By combining theoretical prediction and experimental verification we investigate the piezoelectric properties of yttrium indium nitride (YxIn1-xN). Ab initio calculations show that the YxIn1-xN wurtzite phase is lowest in energy among relevant alloy structures for 0≤x≤0.5. Reactive magnetron sputter epitaxy was used to prepare thin films with Y content up to x=0.51. The composition dependence of the lattice parameters observed in the grown films is in agreement with that predicted by the theoretical calculations confirming the possibility to synthesize a wurtzite solid solution. An AlN buffer layer greatly improves the crystalline quality and surface morphology of subsequently grown YxIn1-xN films. The piezoelectric response in films with x=0.09 and x=0.14 is observed using piezoresponse force microscopy. Theoretical calculations of the piezoelectric properties predict YxIn1−xN to have comparable piezoelectric properties to ScxAl1-xN.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
YInN, Thin films, Sputter deposition, Piezoelectricity, Ab initio calculations
National Category
Condensed Matter Physics Materials Chemistry Inorganic Chemistry Other Materials Engineering Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:liu:diva-125918 (URN)10.1016/j.actamat.2015.11.050 (DOI)000370086500023 ()
Available from: 2016-03-08 Created: 2016-03-08 Last updated: 2017-11-30Bibliographically approved
Ektarawong, A., Simak, S., Hultman, L., Birch, J., Tasnádi, F., Wang, F. & Alling, B. (2016). Effects of configurational disorder on the elastic properties of icosahedral boron-rich alloys based on B6O, B13C2, and B4C, and their mixing thermodynamics. Journal of Chemical Physics, 144(13), Article ID 134503.
Open this publication in new window or tab >>Effects of configurational disorder on the elastic properties of icosahedral boron-rich alloys based on B6O, B13C2, and B4C, and their mixing thermodynamics
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2016 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 144, no 13, article id 134503Article in journal (Refereed) Published
Abstract [en]

The elastic properties of alloys between boron suboxide (B6O) and boron carbide (B13C2), denoted by (B6O)1−x(B13C2)x, as well as boron carbide with variable carbon content, ranging from B13C2 to B4C are calculated from first-principles. Furthermore, the mixing thermodynamics of (B6O)1−x(B13C2)x is studied. A superatom-special quasirandom structure approach is used for modeling different atomic configurations, in which effects of configurational disorder between the carbide and suboxide structural units, as well as between boron and carbon atoms within the units, are taken into account. Elastic properties calculations demonstrate that configurational  disorder in B13C2, where a part of the C atoms in the CBC chains substitute for B atoms in the B12 icosahedra, drastically increase the Young’s and shear modulus, as compared to an atomically ordered state, B12(CBC). These calculated elastic moduli of the disordered state are in excellent agreement with experiments. Configurational disorder between boron and carbon can also explain the experimentally observed almost constant elastic moduli of boron carbide as the carbon content is changed from B4C to B13C2. The elastic moduli of the (B6O)1−x(B13C2)x system are also practically unchanged with composition if boron-carbon disorder is taken into account. By investigating the mixing thermodynamics of the alloys, in which the Gibbs free energy is determined within the mean-field approximation for the configurational entropy, we outline the pseudo-binary phase diagram of (B6O)1−x(B13C2)x. The phase diagram reveals the existence of a miscibility gap at all temperatures up to the melting point. Also, the coexistence of B6O-rich as well as ordered or disordered B13C2-rich domains in the material prepared through equilibrium routes is predicted.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2016
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-122425 (URN)10.1063/1.4944982 (DOI)000374527900023 ()27059576 (PubMedID)
Note

Funding agencies:Swedish Research Council (VR) [621-2011-4417, 330-2014-6336, 2011-42-59]; CeNano at Linkoping University; Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST "MISiS" [K3-2014-049]; LiLi-

At the time for thesis presentation publication was in status: Manuscript

Available from: 2015-11-02 Created: 2015-11-02 Last updated: 2018-08-14Bibliographically approved
Sangiovanni, D., Hellman, O., Alling, B. & Abrikosov, I. (2016). Efficient and accurate determination of lattice-vacancy diffusion coefficients via non equilibrium ab initio molecular dynamics. PHYSICAL REVIEW B, 93(9), 094305
Open this publication in new window or tab >>Efficient and accurate determination of lattice-vacancy diffusion coefficients via non equilibrium ab initio molecular dynamics
2016 (English)In: PHYSICAL REVIEW B, ISSN 2469-9950, Vol. 93, no 9, p. 094305-Article in journal (Refereed) Published
Abstract [en]

We revisit the color-diffusion algorithm [Aeberhard et al., Phys. Rev. Lett. 108, 095901 (2012)] in non equilibrium ab initio molecular dynamics (NE-AIMD) and propose a simple efficient approach for the estimation of monovacancy jump rates in crystalline solids at temperatures well below melting. Color-diffusion applied to monovacancy migration entails that one lattice atom (colored atom) is accelerated toward the neighboring defect site by an external constant force F. Considering bcc molybdenum between 1000 and 2800 K as a model system, NE-AIMD results show that the colored-atom jump rate k(NE) increases exponentially with the force intensity F, up to F values far beyond the linear-fitting regime employed previously. Using a simple model, we derive an analytical expression which reproduces the observed k(NE)(F) dependence on F. Equilibrium rates extrapolated by NE-AIMD results are in excellent agreement with those of unconstrained dynamics. The gain in computational efficiency achieved with our approach increases rapidly with decreasing temperatures and reaches a factor of 4 orders of magnitude at the lowest temperature considered in the present study.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2016
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-127268 (URN)10.1103/PhysRevB.93.094305 (DOI)000372711200003 ()
Note

Funding Agencies|Knut and Alice Wallenberg Foundation [2011.0094]; Swedish Research Council (VR) [621-2011-4417, 2015-04391, 637-2013-7296, 330-2014-336]; Linkoping Linnaeus Initiative LiLi-NFM [2008-6572]; Swedish Government Strategic Research Area Grant in Materials Science on Advanced Functional Materials [MatLiU 2009-00971]; Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Tomsk State University Academic D. I. Mendeleev Fund Program

Available from: 2016-04-20 Created: 2016-04-19 Last updated: 2019-06-28
Kerdsongpanya, S., Eriksson, F., Jensen, J., Lu, J., Sun, B., Kan Koh, Y., . . . Eklund, P. (2016). Experimental and Theoretical Investigation of Cr1-xScxN Solid Solutions for Thermoelectric Applications. Journal of Applied Physics, 120(21), Article ID 215103.
Open this publication in new window or tab >>Experimental and Theoretical Investigation of Cr1-xScxN Solid Solutions for Thermoelectric Applications
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2016 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 120, no 21, article id 215103Article in journal (Refereed) Published
Abstract [en]

We investigate the trends in mixing thermodynamics of Cr1-xScxN solid solutions in the cubic B1 structure and their electronic density of state by first-principle calculations, and thin-film synthesis of Cr1-xScxN solid solutions by reactive dc magnetron sputtering. Films with the composition Cr0.92Sc0.08N exhibit a thermoelectric power factor of about 8x10-4 Wm-1K-2at 770 K, similar to CrN. The results show that the disordered Cr1-xScxN solid solutions is thermodynamically stable in B1 solid solutions at T = 800°C rather than in the B1- L11 ordered solid solutions stable at 0 K. The calculated electronic density of state (DOS) indicates a positive bowing parameter for the electronic band gap of Cr1-xScxN solid solutions. The calculated DOS suggest possible improvement of power factor due to Sc 3d orbital delocalization on Cr 3d orbital gives decreasing electrical resistivity with retained Seebeck coefficient in Cr-rich regime, consistent with the experimentally observed high power factor for the solid solution.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2016
Keywords
Chromium nitride, Scandium nitride, Thermoelectrics, First-principles calculations, Solid solutions
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-117757 (URN)10.1063/1.4968570 (DOI)000390602600026 ()
Note

Funding agencies: European Research Council under the European Communitys Seventh Framework Programme [335383]; Swedish Research Council (VR) [621-2012-4430, 621-2011-4417, 330-2014-6336]; Marie Sklodowska Curie Actions [INCA 60098]; Linnaeus Strong Research Environment Li

Available from: 2015-05-08 Created: 2015-05-08 Last updated: 2017-12-04Bibliographically approved
Mozafari, E., Shulumba, N., Steneteg, P., Alling, B. & Abrikosov, I. A. (2016). Finite-temperature elastic constants of paramagnetic materials within the disordered local moment picture from ab initio molecular dynamics calculations. Physical Review B, 94(5), Article ID 054111.
Open this publication in new window or tab >>Finite-temperature elastic constants of paramagnetic materials within the disordered local moment picture from ab initio molecular dynamics calculations
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2016 (English)In: Physical Review B, ISSN 2469-9950, Vol. 94, no 5, article id 054111Article in journal (Refereed) Published
Abstract [en]

We present a theoretical scheme to calculate the elastic constants of magnetic materials in the high-temperature paramagnetic state. Our approach is based on a combination of disordered local moments picture and ab initio molecular dynamics (DLM-MD). Moreover, we investigate a possibility to enhance the efficiency of the simulations of elastic properties using the recently introduced method: symmetry imposed force constant temperature-dependent effective potential (SIFC-TDEP). We have chosen cubic paramagnetic CrN as a model system. This is done due to its technological importance and its demonstrated strong coupling between magnetic and lattice degrees of freedom. We have studied the temperature-dependent single-crystal and polycrystalline elastic constants of paramagentic CrN up to 1200 K. The obtained results at T = 300 K agree well with the experimental values of polycrystalline elastic constants as well as the Poisson ratio at room temperature. We observe that the Young’s modulus is strongly dependent on temperature, decreasing by 14% from T = 300 K to 1200 K. In addition we have studied the elastic anisotropy of CrN as a function of temperature and we observe that CrN becomes substantially more isotropic as the temperature increases. We demonstrate that the use of Birch law may lead to substantial errors for calculations of temperature induced changes of elastic moduli. The proposed methodology can be used for accurate predictions of mechanical properties of magnetic materials at temperatures above their magnetic order-disorder phase transition.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2016
National Category
Physical Sciences Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-130779 (URN)10.1103/PhysRevB.94.054111 (DOI)000381475300002 ()
Note

Funding agencies. Swedish Research Council (VR) [621-2011-4426, 621-2011-4417, 330-2014-6336]; Swedish Foundation for Strategic Research (SSF) program SRL [10-0026]; Ministry of Education and Science of the Russian Federation [K2-2016-013, 14.Y26.31.0005]; Marie Sklodowska

Available from: 2016-08-23 Created: 2016-08-23 Last updated: 2016-09-26Bibliographically approved
Thore, A., Dahlqvist, M., Alling, B. & Rosén, J. (2016). Magnetic exchange interactions and critical temperature of the nanolaminate Mn2GaC from first-principles supercell methods. Physical Review B, 93(5)
Open this publication in new window or tab >>Magnetic exchange interactions and critical temperature of the nanolaminate Mn2GaC from first-principles supercell methods
2016 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 93, no 5Article in journal (Refereed) Published
Abstract [en]

In this work, we employ and critically evaluate a first-principles approach based on supercell calculations for predicting the magnetic critical order-disorder temperature 𝑇𝑐 . As a model material we use the recently discovered nanolaminate Mn2GaC.

First, we derive the exchange interaction parameters 𝐽𝑖𝑗 between pairs of Mn atoms on sites 𝑖 and 𝑗 of the bilinear Heisenberg Hamiltonian using the novel magnetic direct cluster averaging method (MDCA), and then compare the 𝐽’s from the MDCA calculations to the same parameters calculated using the Connolly-Williams method. We show that the two methods yield closely matching results, but observe that the MDCA method is computationally less effective when applied to highly ordered phases such as Mn2GaC.

Secondly, Monte Carlo simulations are used to derive the magnetic energy, specific heat, and 𝑇𝑐 . For Mn2GaC, we find 𝑇𝑐 = 660 K. The uncertainty in the calculated 𝑇𝑐 caused by possible uncertainties in the 𝐽’s is discussed and exemplified in our case by an analysis of the impact of the statistical uncertainties of the MDCA-derived 𝐽’s, resulting in a 𝑇𝑐 distribution with a standard deviation of 133 K.

National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-124563 (URN)10.1103/PhysRevB.93.054432 (DOI)000371391800004 ()
Note

Funding agencies: European Research Council under the European Community Seventh Framework Program (FP7)/ERC Grant [258509]; Swedish Research Council (VR) [621-2011-4417, 330-2014-6336]; Knut and Alice Wallenberg (KAW) Fellowship program; SSF synergy grant FUNCASE

Available from: 2016-02-03 Created: 2016-02-03 Last updated: 2017-11-30Bibliographically approved
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