Magnetism in La substituted Sr hexaferrite -: art. no. 10F309

The electronic structure of LaSr(1-x)Fe(12)O(19) (x=O, 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 Fe 3d electrons. Fe-sublattice preferences for the magnetic moments introduced by La substitution were calculated. The results are compared with measurements of the magnetization performed in a vibrating sample magnetometer at 4.2 K, from which the magnetic moment per unit cell of La hexaferrite was derived. The calculations were started in order to find an explanation for the extraordinary behavior of the magnetocrystalline anisotropy of La containing M-type hexaferrites, which was confirmed by singular point detection measurements. (c) 2005 American Institute of Physics.