Optical Spectroscopy of Rare Earth Perovskites

Abstract

High‐resolution optical absorption spectra have been obtained on antiferromagnetic DyAlO₃ and weakly ferromagnetic HoFeO₃ and DyFeO₃ at low temperatures. In DyAlO₃ the absorption lines show a triplet structure which vanishes in Y(Dy)AlO₃. From this it is concluded that the magnetic interactions take place for each Dy ion with only two neighbors. At 3.5°K the splitting of the absorption lines starts to increase with decreasing temperature yielding a Néel temperature of (3.5±0.1)°K. The magnetic moment of the ground state is determined to be μ = (8.6±1.0)μ_B. In DyFeO₃ a Néel temperature of (4.5±0.3)°K is deduced from the temperature dependent lineshift, the magnetic moment of the ground state is found to be μ = (8.9±1.0)μ_B.