Lattice-ion interactions of Ti3+ in corundum I. The Jahn-Teller effect and the theory of the effects of electric field and strain

Abstract

The magnetic properties of a Ti³⁺ ion in an Al₂O₃ lattice are discussed using a dynamic Jahn-Teller model in which an orbital triplet interacts with the vibrational E modes of the ligands. Calculations of the effect of applied electric field and strain on the electron paramagnetic resonance spectra are made. It is found that second-order vibronic effects are very important in both cases. The linear electric field effect gives rise to large g shifts of the order 10^-4 for an applied electric field of 1 kv cm^-1 while the strain tensors are of order 10² per unit strain. Comparison is made with experimental results.