Magnetic Effects in the Optical Spectrum of MnF2

Abstract

Sharp optical transitions between the ⁶A_1g (ground state) and the ⁴T_1g(⁴G) levels of MnF₂ have been studied as a function of temperature (2°–40°K) and magnetic field (0–10 kOe) in both emission and absorption. Properties suggesting that two emission lines are spin‐wave sidebands are discussed. Temperature‐dependent shifts of the spectra are attributed to the antiferromagnetic nature of the crystal. A simple molecular field model is presented which describes the magnetic field behavior of the absorption spectra.