High-frequency EPR of Cr2+ ions in CdGa2S4

Abstract

High-frequency broad-band (65–240 GHz) EPR is used to study impurity centers of bivalent chromium in a CdGa2S4 crystal. It is found that the EPR spectra correspond to tetragonal symmetry. The spin Hamiltonian H = βB · g · S + B 2 0 O 2 0 + B 4 0 O 4 0 + B 4 4 O 4 4 with the parameters B 2 0 =23659±2 MHz, B 4 0 =1.9±1 MHz, |B 4 4 |=54.2±2 MHz, g ‖=1.93±0.02, and g ⊥=1.99±0.02 is used to describe the observed spectra. It is concluded that chromium ions occupy one of the tetrahedrally coordinated cation positions.