Regensburg 2025 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 9: Poster

MM 9.34: Poster

Monday, March 17, 2025, 18:30–20:30, P1

Generalized susceptibility expressed by Wannier functions — •Dominik Váňa and Jaroslav Hamrle — Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, Prague

The generalized susceptibility describes the tendency (energy stability) of the cubic phase to become modulated. A typical example is the modulation of Ni₂MnGa [1] which can undergo structural transformation from austenite to a modulated structure. The generalized susceptibility is calculated using occupation probability (Fermi-Dirac distribution), however, this approach omits the dependence which the coupling coefficient of the electron-lattice interaction has on electronic states. The goal of this work is to express generalized susceptibility with calculated coupling coefficients. As the first step, we express generalized susceptibility using Wannier functions, modifying the original approach of Motizuki [2], based on a linear combination of atomic orbitals.

• [1] O. Söderberg et al, Ni-Mn-Ga multifunctional compounds, Mater. Sci. Eng. A 481, 80 (2008)
• [2] K. Motizuki, N. Suzuki, Microscopic Theory of Structural Phase Transitions in Layered Transitional-Metal Compounds, D. Reidel Publishing Company (1986)

Keywords: Generalized susceptibility; Mechanical instability; Wannier functions; Twinning