Eur. Phys. J. B 43, 509-515 (2005)
https://doi.org/10.1140/epjb/e2005-00084-8

Magnetism of mixed valence (LaSr) hexaferrites

¹ Institute of Physics of ASCR, Cukrovarnická 10, 162 53 Prague 6, Czech Republic
² Institute for Solid State Physics, Technical University Vienna, Wiedner Hauptstrasse 8-10, 1040 Vienna, Austria

Corresponding author: ^a novakp@fzu.cz

Received: 27 August 2004
Revised: 18 January 2005
Published online: 30 March 2005

Abstract

The electronic structure of La_xSrFe₁₂O₁₉ (x=0, 0.25, 0.5, 0.75, 1) hexaferrite is calculated using the density functional theory and generalized gradient approximation (GGA). The GGA+U method is used to improve the description of strongly correlated 3d electrons of Fe. The `virtual crystal' approach is employed for the fractional x, its applicability is checked for x=0.5 by comparing it with the supercell method. The electronic charges introduced by the La substitution show no significant preference for any of the iron sublattices. The magnetic moment decreases linearly with the increasing La content in agreement with the experiment.