Dresden 2009 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 13: Poster Ia: Electron Theory (1); Magnetic Imaging (2,3); Thin Films (4-25); MSMA (26-33); Magn. Semiconductors (34-42); Magn. Half Metals and Oxides (43-60)

MA 13.24: Poster

Dienstag, 24. März 2009, 10:15–13:00, P1A

Geometry and magnetic structure of uranium along the tetragonal epitaxial Bain path — •Stephan Schönecker, Manuel Richter, Klaus Koepernik, and Helmut Eschrig — IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany

Epitaxially manufactured structures grown pseudomorphically on suitable substrates provide a way to stabilise non-equilibrium structures of materials. This includes grown films which posses a large lattice misfit between substrate and film material under equilibrium conditions, but also if the structure grown differs from the equilibrium structure of the bulk film material. Large misfits do not necessarily mean large lateral stress. Theory can help to predict e.g. geometry, stresses and magnetic properties of pseudomorphically grown metal films. In this work, we considered the epitaxial Bain path (e.g. [1]) of elemental uranium, which provides a reasonable description of tetragonally distorted films on substrates. We employed density functional calculation in the implementation of the full potential local orbital program package FPLO [2]. We found three meta-stable tetragonal phases, in addition a ferromagnetic state close to the fcc phase.

[1] P. M. Marcus, F. Jona, and S. L. Qiu, Phys. Rev. B 66, 064111 (2002)

[2] K. Koepernik and H. Eschrig, Phys. Rev. B 59, 1743 (1999);
http://www.fplo.de