Electron Paramagnetic Resonance of Cr3+ Ions in ABO3 (A = Sc, In, Ga) Diamagnetic Crystals

A magnetic resonance method is applied to the investigation of a number of isostructural diamagnetic compounds ABO3 (A = Sc, In, and Ga) with small additions of Cr3+ ions (S = 3/2) sufficient to observe single-ion and pair spectra. It is shown that the resonance spectra for isolated Cr3+ ions can be described to a good accuracy by the ordinary axial spin Hamiltonian for 3d ions in octahedral oxygen environment. The parameters of the spin Hamiltonian are determined for single Cr3+ ion and Cr3+–Cr3+ pair. Lattice distorsions of the parent ABO3 crystals caused by the Cr3+ impurities is discussed.