MAGNETOOPTICAL PROPERTIES OF YIG-SC SINGLE-CRYSTALS

Faraday rotation measurements at 1152 nm were performed on single-crystal oriented platelets of ferrimagnetic garnets of formula Y3Fe5-xScxO12 (0<x<0.55) as a function of temperature and magnetic field. Sc3+ ions substituting for octahedral Fe3+ have a much greater influence on the spontaneous Faraday rotation than found for the corresponding tetrahedral diamagnetic substitution. The Faraday rotation susceptibility is constant and independent of Sc concentration. The results are interpreted as the sum of magneto-optical contributions from the [a] and (d) sublattices proportional to their magnetizations and induced by magnetic and electric dipole transitions. The electric magneto-optical coefficients deduced from a least squares fit of the experimental values are linear functions of the Sc concentration.