Measurement of Fe-Ga ion interchange by pulsed laser heating and fast cooling of magnetic bubble films

Abstract

Relaxation times ranging from 10−4 to 10−3 s at 1200–1400 °C for Ga3+-Fe3+ site interchange have been measured by laser annealing of magnetic bubble (yttrium iron-gallium garnet) films. Laser annealing with a square pulse in time allows rapid heating and, more importantly, even more rapid cooling of the film to freeze in the high-temperature state reached. Different equilibrium site distributions and shorter relaxation times compared to previous measurements are attributed to fast oxygen diffusion out of the films, with an increased site switching rate resulting from the higher oxygen vacancy density.