Ground-state energy and zero-field splitting parameters in GeFe2O4 crystal

Abstract

GeFe2O4 is a spinel-type compound in which the neighborhoo d of a Fe2+ ion has a trigonal symmetry with respect to an axis which is parallel to one of the three 〈111〉 direction,and varies from site to site . The crystal-field and spin-orbit complete Hamiltonian matrix of 3d4/3d6 ions ha ve been establishe d by irreducible representation method, The zero-field splitting parameters D an d F-a of Fe2+ ions in GeFe2O4 crystal are prese nted by using the cryst al-field and spin-orbit interaction complete diagonalizing Hamiltonian matrix wi th the theory of electron paramagnetic resonance; at the same time, the contribu tions to zero-field splitting from spin-triplet state have been studied. The res ults show that the contributions to zero-field splitting from spin-triplet state are important and strong. The calculated results are in good agreement with the experimental data.