Annealing effects on cation distribution in diamagnetically substituted single crystal Yttrium Iron Garnet

The cation distribution in Ga, Al and Sc substituted YIG has been determined from measurements at 295K and 77K of annealed and quenched spheres made from single crystals. The effects of thermal treatment on show quantitatively agreement with calculations from the molecular field theory and Borghese\´s thermodynamic equilibrium expression. The stabilization energies describing quantitatively the lattice site preference of the substituted cations have been determined to: eV for Ga, eV for Al and eV for Sc. The observed kinetics of the cation transfer strongly depend on the temperature, the kind of cation substituted and on the defect concentration. Annealing in inert and reducing atmosphere decreases the relaxation rate of the redistribution by several orders of magnitude. FMR linewidth data indicate the creation of Fe²⁺which is known to enhance rigorously the cation transfer.