Regensburg 2022 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 11: Computational Magnetism 1

MA 11.4: Vortrag

Montag, 5. September 2022, 15:45–16:00, H48

Ab initio study of exchange interactions at planar defects of crystal lattices — •Martin Zelený¹, Monika Všianská², Denis Ledue³, Renaud Patte³, Miroslav Černý⁴, Ladislav Straka⁵, and Oleg Heczko⁵ — ¹Institute of Materials Science and Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic — ²Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic — ³Normandie Université, UNIROUEN, INSA Rouen, CNRS, GPM, Saint Étienne du Rouvray, France — ⁴Central European Institute of Technology, Brno University of Technology, Czech Republic — ⁵FZU - Institute of Physics of the Czech Academy of Sciences, Czech Republic

Planar defects play an important role in crystalline magnetic materials, because they serve as obstacles to magnetic domain wall motion. Atomistic description of the magnetic properties requires knowledge of exchange interaction parameters J_ij between two atomic sites. These parameters can be found in literature for many bulk magnetic materials. However, very little is known about J_ij in the vicinity of planar defects where the symmetry of crystal lattice is reduced and atoms have different chemical environment. We provide deep analysis of J_ij obtained from ab initio calculations in the vicinity of the clean Σ5(310) grain boundary in bcc Fe as well as grain boundary with segregated P impurities. We analyze also J_ij parameters in the vicinity of twin boundaries and antiphase boundaries in Ni₂MnGa magnetic shape memory alloys. Our results show strong influence of planar defects on exchange interactions.