Laser annealing of epitaxial garnet films under controlled atmospheres

Abstract

Epitaxial films with a composition of Eu0.54Y 2.41Pb0.03Fe3.84Ga1.18O 12 have been laser annealed in forming gas, nitrogen, air and oxygen. Annealed films were studied using bubble statics, ferromagnetic resonance and x-ray techniques. Changes in the annealing ambient resulted in variations in the maximum saturation magnetization (4πMs) achieved, and in the laser power thresholds for film cracking and melting. In comparison with other atmospheres, oxygen allowed the use of greater laser power without film damage and yielded the highest saturation magnetization. The increase in 4πM s (above the as-grown value) produced by annealing in oxygen was more than 30% larger than achieved in air and more than 50% larger than reached in forming gas or nitrogen. The influence of an ambient is interpreted in terms of its abbility to suppress the formation of oxygen vacancies during laser annealing.