title: Quantum theory of the anisotropy of the magnetic properties of ferrimagnetic holmium iron garnet single crystals.
abstract: The pronounced anisotropy of the magnetization caused by the Ho(3+) ions in the ferrimagnetic holmium iron garnet has been investigated based on quantum theory. The strong anisotropy of the magnetization of the Ho(3+) ions originates mainly from the effect of the crystal field upon the Ho(3+) ions and the anisotropic Ho(3+)-Fe(3+) superexchange interaction. Following the expression of the Yb(3+)-Fe(3+) exchange interaction used by Alben, the anisotropy of the Ho(3+)-Fe(3+) exchange interaction is defined by three principal values of the exchange tensor G. Because the six Ho(3+) sublattices are magnetically non-equivalent, we calculate the magnetic quantities of the Ho(3+) at the six sublattices and compare the average value of the so-obtained six quantities with the measured values. The calculated results are in good agreement with experiments. An interpretation on the anisotropy of the magnetic properties of HoIG is given.
authors.affiliation: College of Physics and Electronic Information, Luoyang Normal University, Luoyang 471022, People's Republic of China.
authors.forename: Jiehui
authors.initials: J
authors.lastname: Yang
authors.forename: Shengcan
authors.initials: S
authors.lastname: Ma
authors.forename: You
authors.initials: Y
authors.lastname: Xu