liu.seSearch for publications in DiVA
Change search
Link to record
Permanent link

Direct link
BETA
Steneteg, Peter
Alternative names
Publications (10 of 16) Show all publications
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
Show others...
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
Abrikosov, I., Ponomareva, A. V., Steneteg, P., Barannikova, S. A. & Alling, B. (2016). Recent progress in simulations of the paramagnetic state of magnetic materials. Current opinion in solid state & materials science, 20(2), 85-106
Open this publication in new window or tab >>Recent progress in simulations of the paramagnetic state of magnetic materials
Show others...
2016 (English)In: Current opinion in solid state & materials science, ISSN 1359-0286, E-ISSN 1879-0348, Vol. 20, no 2, p. 85-106Article, review/survey (Refereed) Published
Abstract [en]

We review recent developments in the field of first-principles simulations of magnetic materials above the magnetic order disorder transition temperature, focusing mainly on 3d-transition metals, their alloys and compounds. We review theoretical tools, which allow for a description of a system with local moments, which survive, but become disordered in the paramagnetic state, focusing on their advantages and limitations. We discuss applications of these theories for calculations of thermodynamic and mechanical properties of paramagnetic materials. The presented examples include, among others, simulations of phase stability of Fe, Fe-Cr and Fe-Mn alloys, formation energies of vacancies, substitutional and interstitial impurities, as well as their interactions in Fe, calculations of equations of state and elastic moduli for 3d-transition metal alloys and compounds, like CrN and steels. The examples underline the need for a proper treatment of magnetic disorder in these systems. (C) 2015 Elsevier Ltd. All rights reserved.

Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD, 2016
Keywords
Paramagnetic state; Magnetic materials; First-principles simulations
National Category
Physical Sciences Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-127416 (URN)10.1016/j.cossms.2015.07.003 (DOI)000372760600003 ()
Note

Funding Agencies|Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Tomsk State University Academic D.I. Mendeleev Fund Program [8.1.18.2015]; Swedish Foundation for Strategic Research (SSF) program SRL Grant [10-0026]; Swedish Research Council (VR) [621-2011-4426, 621-2011-4417]; Program of Fundamental Research of State Academies of Sciences [III.23.1.2]

Available from: 2016-05-02 Created: 2016-04-26 Last updated: 2017-11-30
Sangiovanni, D., Alling, B., Steneteg, P., Hultman, L. & Abrikosov, I. (2015). Nitrogen vacancy, self-interstitial diffusion, and Frenkel-pair formation/dissociation in B1 TiN studied by ab initio and classical molecular dynamics with optimized potentials. Physical Review B. Condensed Matter and Materials Physics, 91(5), 054301
Open this publication in new window or tab >>Nitrogen vacancy, self-interstitial diffusion, and Frenkel-pair formation/dissociation in B1 TiN studied by ab initio and classical molecular dynamics with optimized potentials
Show others...
2015 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 91, no 5, p. 054301-Article in journal (Refereed) Published
Abstract [en]

We use ab initio and classical molecular dynamics (AIMD and CMD) based on the modified embedded-atom method (MEAM) potential to simulate diffusion of N vacancy and N self-interstitial point defects in B1 TiN. TiN MEAM parameters are optimized to obtain CMD nitrogen point-defect jump rates in agreement with AIMD predictions, as well as an excellent description of TiNx (similar to 0.7 less than x less than= 1) elastic, thermal, and structural properties. We determine N dilute-point-defect diffusion pathways, activation energies, attempt frequencies, and diffusion coefficients as a function of temperature. In addition, the MD simulations presented in this paper reveal an unanticipated atomistic process, which controls the spontaneous formation of N self-interstitial/N vacancy (N-I/N-V) pairs (Frenkel pairs), in defect-free TiN. This entails that the N lattice atom leaves its bulk position and bonds to a neighboring N lattice atom. In most cases, Frenkel-pair N-I and N-V recombine within a fraction of ns; similar to 50% of these processes result in the exchange of two nitrogen lattice atoms (N-N-Exc). Occasionally, however, Frenkel-pair N-interstitial atoms permanently escape from the anion vacancy site, thus producing unpaired N-I and N-V point defects.

Place, publisher, year, edition, pages
American Physical Society, 2015
National Category
Physical Sciences Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-114567 (URN)10.1103/PhysRevB.91.054301 (DOI)000348872600002 ()
Note

Funding Agencies|Knut and Alice Wallenberg Foundation [2011.0094]; Swedish Research Council (VR) Linkoping Linnaeus Initiative LiLi-NFM [2008-6572]; Swedish Government Strategic Research Area Grant in Materials Science on Advanced Functional Materials through Swedens innovation agency VINNOVA [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: 2015-03-02 Created: 2015-02-26 Last updated: 2019-06-28
Mozafari, E., Alling, B., Steneteg, P. & Abrikosov, I. (2015). Role of N defects in paramagnetic CrN at finite temperatures from first principles. Physical Review B. Condensed Matter and Materials Physics, 91(9), 094101
Open this publication in new window or tab >>Role of N defects in paramagnetic CrN at finite temperatures from first principles
2015 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 91, no 9, p. 094101-Article in journal (Refereed) Published
Abstract [en]

Simulations of defects in paramagnetic materials at high temperature constitute a formidable challenge to solid-state theory due to the interaction of magnetic disorder, vibrations, and structural relaxations. CrN is a material where these effects are particularly large due to a strong magnetolattice coupling and a tendency for deviations from the nominal 1: 1 stoichiometry. In this work, we present a first-principles study of nitrogen vacancies and nitrogen interstitials in CrN at elevated temperature. We report on formation energetics, the geometry of interstitial nitrogen dimers, and the impact on the electronic structure caused by the defects. We find a vacancy formation energy of 2.28 eV with a small effect of temperature, i.e., a formation energy for N interstitial in the form of a less than 111 greater than -oriented split bond of 3.77 eV with an increase to 3.97 at 1000 K. Vacancies are found to add three electrons, while split-bond interstitial adds one electron to the conduction band. The band gap of defect-free CrN is smeared out due to vibrations, although it is difficult to draw a conclusion about the exact temperature at which the band gap closes from our calculations. However, it is clear that at 900 K there is a nonzero density of electronic states at the Fermi level. At 300 K, our results indicate a border case where the band gap is about to close.

Place, publisher, year, edition, pages
American Physical Society, 2015
National Category
Physical Sciences Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-116954 (URN)10.1103/PhysRevB.91.094101 (DOI)000350994400001 ()
Note

Funding Agencies|Swedish Research Council (VR) [621-2011-4426]; Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Tomsk State University Academic D. I. Mendeleev Fund Program; VR [621-2011-4417]

Available from: 2015-04-13 Created: 2015-04-10 Last updated: 2017-12-04
Shulumba, N., Alling, B., Hellman, O., Mozafari, E., Steneteg, P., Odén, M. & Abrikosov, I. (2014). Vibrational free energy and phase stability of paramagnetic and antiferromagnetic CrN from ab initio molecular dynamics. Physical Review B. Condensed Matter and Materials Physics, 89(17), 174108
Open this publication in new window or tab >>Vibrational free energy and phase stability of paramagnetic and antiferromagnetic CrN from ab initio molecular dynamics
Show others...
2014 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 89, no 17, p. 174108-Article in journal (Refereed) Published
Abstract [en]

We present a theoretical first-principles method to calculate the free energy of a magnetic system in its high-temperature paramagnetic phase, including vibrational, electronic, and magnetic contributions. The method for calculating free energies is based on ab initio molecular dynamics and combines a treatment of disordered magnetism using disordered local moments molecular dynamics with the temperature-dependent effective potential method to obtain the vibrational contribution to the free energy. We illustrate the applicability of the method by obtaining the anharmonic free energy for the paramagnetic cubic and the antiferromagnetic orthorhombic phases of chromium nitride. The influence of lattice dynamics on the transition between the two phases is demonstrated by constructing the temperature-pressure phase diagram.

Place, publisher, year, edition, pages
American Physical Society, 2014
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-110985 (URN)10.1103/PhysRevB.89.174108 (DOI)000341308600001 ()
Note

Funding Agencies|Erasmus Mundus Joint European Doctoral Programme DocMASE; SECO Tools AB; Swedish Research Council [621-2011-4426, 621-2011-4417]; Swedish Foundation for Strategic Research (SSF) programs SRL [10-0026]; project Designed Multicomponent Coatings (MultiFilms); Knut and Alice Wallenberg Foundation (KAW)

Available from: 2014-10-01 Created: 2014-10-01 Last updated: 2017-12-05Bibliographically approved
Abrikosov, I. A., Alling, B., Steneteg, P., Hultberg, L., Hellman, O., Yu Mosyagin, I., . . . Barannikova, S. A. (2013). Finite Temperature, Magnetic, and Many-Body Effects in Ab Initio Simulations of Alloy Thermodynamics. In: TMS2013 Supplemental Proceedings: (pp. 617-626). John Wiley & Sons
Open this publication in new window or tab >>Finite Temperature, Magnetic, and Many-Body Effects in Ab Initio Simulations of Alloy Thermodynamics
Show others...
2013 (English)In: TMS2013 Supplemental Proceedings, John Wiley & Sons, 2013, p. 617-626Chapter in book (Refereed)
Abstract [en]

Ab initio electronic structure theory is known as a useful tool for prediction of materials properties. However, majority of simulations still deal with calculations in the framework of density functional theory with local or semi-local functionals carried out at zero temperature. We present new methodological solution.s, which go beyond this approach and explicitly take finite temperature, magnetic, and many-body effects into account. Considering Ti-based alloys, we discuss !imitations of the quasiharmonic approximation for the treatment of lattice vibrations, and present an accurate and easily extendable method to calculate free ,energies of strongly anharmonic solids. We underline the necessity to going beyond the state-of-the-art techniques for the determination of effective cluster interactions in systems exhibiting mctal-to-insulator transition, and describe a unified cluster expansion approach developed for this class of materials. Finally, we outline a first-principles method, disordered local moments molecular dynamics, for calculations of thermodynamic properties of magnetic alloys, like Cr1-x,.AlxN, in their high-temperature paramagnetic state. Our results unambiguously demonstrate importance of finite temperature effects in theoretical calculations ofthermodynamic properties ofmaterials.

Place, publisher, year, edition, pages
John Wiley & Sons, 2013
Keywords
Alloy thermodynamics, Ti alloys, (Ti-Al)N, (Cr-Al)N
National Category
Condensed Matter Physics Theoretical Chemistry Inorganic Chemistry Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:liu:diva-136443 (URN)10.1002/9781118663547.ch77 (DOI)9781118605813 (ISBN)9781118663547 (ISBN)
Available from: 2017-04-10 Created: 2017-04-10 Last updated: 2017-11-01Bibliographically approved
Steneteg, P., Hellman, O., Vekilova, O., Shulumba, N., Tasnádi, F. & Abrikosov, I. (2013). Temperature dependence of TiN elastic constants from ab initio molecular dynamics simulations. Physical Review B. Condensed Matter and Materials Physics, 87(9)
Open this publication in new window or tab >>Temperature dependence of TiN elastic constants from ab initio molecular dynamics simulations
Show others...
2013 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 87, no 9Article in journal (Refereed) Published
Abstract [en]

Elastic properties of cubic TiN are studied theoretically in a wide temperature interval. First-principles simulations are based on ab initio molecular dynamics (AIMD). Computational efficiency of the method is greatly enhanced by a careful preparation of the initial state of the simulation cell that minimizes or completely removes a need for equilibration and therefore allows for parallel AIMD calculations. Elastic constants C11, C12, and C44 are calculated. A strong dependence on the temperature is predicted, with C11 decreasing by more than 29% at 1800 K as compared to its value obtained at T=0 K. Furthermore, we analyze the effect of temperature on the elastic properties of polycrystalline TiN in terms of the bulk and shear moduli, the Young's modulus and Poisson ratio. We construct sound velocity anisotropy maps, investigate the temperature dependence of elastic anisotropy of TiN, and observe that the material becomes substantially more isotropic at high temperatures. Our results unambiguously demonstrate the importance of taking into account finite temperature effects in theoretical calculations of elastic properties of materials intended for high-temperature applications.

Place, publisher, year, edition, pages
American Physical Society, 2013
National Category
Natural Sciences Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-78754 (URN)10.1103/PhysRevB.87.094114 (DOI)000316791600001 ()
Note

Funding Agencies|Swedish Research Council|621-2008-5535621-2011-4426|Swedish Foundation for Strategic Research (SSF) programs|10-0026|project Designed Multicomponent Coatings (MultiFilms)||Erasmus Mundus doctoral program DocMase||Ministry of Education and Science of the Russian Federation within the framework of Program Research and Pedagogical Personnel for Innovative Russia|14.B37.21.089010.09.2012|

Available from: 2012-06-20 Created: 2012-06-20 Last updated: 2017-12-07Bibliographically approved
Hellman, O., Steneteg, P., Abrikosov, I. & Simak, S. (2013). Temperature dependent effective potential method for accurate free energy calculations of solids. Physical Review B. Condensed Matter and Materials Physics, 87(10)
Open this publication in new window or tab >>Temperature dependent effective potential method for accurate free energy calculations of solids
2013 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 87, no 10Article in journal (Refereed) Published
Abstract [en]

We have developed a thorough and accurate method of determining anharmonic free energies, the temperature dependent effective potential technique (TDEP). It is based on ab initio molecular dynamics followed by a mapping onto a model Hamiltonian that describes the lattice dynamics. The formalism and the numerical aspects of the technique are described in detail. A number of practical examples are given, and results are presented, which confirm the usefulness of TDEP within ab initio and classical molecular dynamics frameworks. In particular, we examine from first principles the behavior of force constants upon the dynamical stabilization of the body centered phase of Zr, and show that they become more localized. We also calculate the phase diagram for 4He modeled with the Aziz et al. potential and obtain results which are in favorable agreement both with respect to experiment and established techniques.

Place, publisher, year, edition, pages
American Physical Society, 2013
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-91545 (URN)10.1103/PhysRevB.87.104111 (DOI)000316665300002 ()
Note

Funding Agencies|Knut & Alice Wallenberg Foundation (KAW) project "Isotopic Control for Ultimate Material Properties"||Swedish Research Council (VR)|621-2011-4426|LiLi-NFM||Swedish Foundation for Strategic Research (SSF) program|SRL10-0026|Ministry of Education and Science of the Russian Federation within the framework of Program Scientific and Scientific-Pedagogical Personnel for Innovative Russia|14.B37.21.089014.A18.21.0893|Swedish Government Strategic Research Area Grant in Materials Science||

Available from: 2013-04-26 Created: 2013-04-26 Last updated: 2017-12-06
Alling, B., Steneget, P., Tholander, C., Tasnádi, F., Petrov, I., Greene, J. E. & Hultman, L. (2012). Configurational disorder effects on adatom mobilities on Ti1-xAlxN(001) surfaces from first principles. Physical Review B. Condensed Matter and Materials Physics, 85(24), 245422
Open this publication in new window or tab >>Configurational disorder effects on adatom mobilities on Ti1-xAlxN(001) surfaces from first principles
Show others...
2012 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 85, no 24, p. 245422-Article in journal (Refereed) Published
Abstract [en]

We use metastable NaCl-structure Ti0.5Al0.5N alloys to probe effects of configurational disorder on adatom surface diffusion dynamics which control phase stability and nanostructural evolution during film growth. First-principles calculations were employed to obtain energy potential maps of Ti and Al adsorption on an ordered TiN(001) reference surface and a disordered Ti0.5Al0.5N(001) solid-solution surface. The energetics of adatom migration on these surfaces are determined and compared to isolate effects of configurational disorder. The results show that alloy surface disorder dramatically reduces Ti adatom mobilities. Al adatoms, in sharp contrast, experience only small disorder-induced differences in migration dynamics.

Place, publisher, year, edition, pages
american physical society, 2012
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-78822 (URN)10.1103/PhysRevB.85.245422 (DOI)000305089700007 ()
Available from: 2012-06-21 Created: 2012-06-21 Last updated: 2017-12-07Bibliographically approved
Steneteg, P. (2012). Development of molecular dynamics methodology for simulations of hard materials. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Development of molecular dynamics methodology for simulations of hard materials
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis is focused on molecular dynamics simulations, both classical and ab initio. It is devoted to development of new methods and applications of molecular dynamics based techniques to a series of materials, all of which have the common property of being hard.

I first study grain boundaries in diamond and apply a novel method to better explore the configurational phase space. Using this method several new grain boundary structures are found. The lowest energy grain boundary structure has 20% lower energy then the one obtained with a conventional approach.

Another area is the development of efficient methods for first principles Born-Oppenheimer molecular dynamics. Here a fundamental shortcoming of the method that limits efficiency and introduces drift in the total energy of the system, is addressed and a solution to the problem is presented. Special attention is directed towards methods based on plane waves. The new molecular dynamics simulation method is shown to be more efficient and conserves the total energy orders of magnitude better then previous methods.

The calculation of properties for paramagnetic materials at elevated temperature is a complex task. Here a new method is presented that combines the disordered local moments model and ab initio molecular dynamics. The method is applied to calculate the equation of state for CrN were the connection between magnetic state and atomic structure is very strong. The bulk modulus is found to be very similar for the paramagnetic cubic and the antiferromagnetic orthorhombic phase.

TiN has many applications as a hard material. The effects of temperature on the elastic constants of TiN are studied using ab initio molecular dynamics. A significant dependence on temperature is seen for all elastic constants, which decrease linearly with temperature.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2012. p. 69
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1454
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-78823 (URN)978-91-7519-883-5 (ISBN)
Public defence
2012-06-08, Planck, Fysikhuset, Campus Valla, Linköpings universitet, Linköping, 10:00 (English)
Opponent
Supervisors
Available from: 2012-06-21 Created: 2012-06-21 Last updated: 2012-06-21Bibliographically approved
Organisations

Search in DiVA

Show all publications