Effect of a Jahn-Teller ion on the ground states of Fe2+ and Ni2+ ions in spinel ferrites

Abstract

The influence of crystal distortion due to a Jahn-Teller mechanism on lattice constant, Curie temperature, magnetization, and geff has been investigated by substituting Cu2+ ions in FeZn and NiZn ferrites. The observed results have been analyzed on the basis of exchange, spin orbit, and Jahn-Teller mechanisms. The changes exhibited on copper substitution in the two spinels have sharp differences. These have been attributed to the difference in the ground state of the divalent ions.