Fine Structure of Fe2+ Multiplets, Magnetic Anisotropy, and Interrelation between Magnetic and Electric Structures in Fe2Mo3O8

Abstract

The effective Hamiltonians of the fine structure of Fe²⁺ (⁵D) terms are derived using the methods of operator perturbation theory taking into account covalent bonds between iron and oxygen ions. The energy operators of coupling of magnetic and electric dipole moments with the electric field are obtained for states of multiplets Fe²⁺ (⁵E) and Fe²⁺ (⁵T₂) with minimal sets of parameters. The energy spectra of low-lying states, the magnetic anisotropy parameters, and the distribution of quadrupole and induced electric dipole moments over all positions in the unit cell are calculated. The results of calculations are compared with available experimental data.