Dresden 2009 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 46: Electronic Properties II

MM 46.2: Vortrag

Donnerstag, 26. März 2009, 17:00–17:15, IFW B

Structural and magnetic properties of Fe under pressure — •Sergey Mankovsky, Jan Minar, Svitlana Polesya, and Hubert Ebert — Dept. Chemie und Biochemie/Phys. Chemie, Universität München, München, Deutschland

The structural bcc→hcp phase transition in Fe under pressure has been investigated on the basis of ab-initio electronic structure calculations using the KKR Green’s function method. The role of the magnetic order on the stability of the bcc structure was studied. For this purpose an analysis of the total energy and magnetic structure was performed at different pressure values along a transformation path connecting the bcc and hcp structures. This allows an explanation of the small differences in pressure dependent structural and magnetic XAS signals observed experimentally. In addition, calculations of phonon spectra at different pressure values have been performed. They are based on the formalism of the calculation of the real-space force-constant tensor within the KKR Green’s function method. An analysis of different contributions to the dynamical matrix shows the responsibility of the exchange splitting of spin-up and spin-down energy bands for the stabilisation of bcc structure at low pressure.