Berlin 2018 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 13: Focus Session: Magnetism in Materials Science: Thermodynamics, Kinetics and Defects II (joint session MM/MA)

MA 13.3: Vortrag

Montag, 12. März 2018, 16:30–16:45, TC 010

Ab initio study of magnetic states in superalloy nanocomposite phase Fe₂AlTi — •Anton Slávik^1,2, Ivana Miháliková^1,2, Martin Friák^1,2, David Holec³, Monika Všianská^1,4,5, and Mojmír Šob^4,1,5 — ¹Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Brno, Czech Republic — ²Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Brno, Czech Republic — ³Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Leoben, Austria — ⁴Central European Institute of Technology, CEITEC MU, Masaryk University, Brno, Czech Republic — ⁵Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic

The Fe₂AlTi intermetallic compound is one of Heusler L2₁-structure materials possessing interesting magnetic properties. We study thermodynamic, electronic, structural and elastic properties of different magnetic states in Fe₂AlTi by ab initio fixed-spin-moment calculations. A spin-polarized ferrimagnetic state with the magnetic moment of 0.925 µ_B per formula unit is found to be a stable energy minimum at T=0 K. Interestingly, a non-magnetic state has its total energy only by 10.6 meV/atom higher and, consequently, the lowest energy state is found very sensitive to different perturbations. We discuss this weak stability in the case of fairly high statistical probability of occurrence of the non-magnetic state, trigonal strains (to which Fe₂AlTi has a compression-tension asymmetric response), off-stoichiometry and point defects as well as interfaces within Fe-Al-Ti superalloy nano-composites.