Magneto-optical properties of nanometer crystal giant magneto-optical BiAlDyIG thin film materials post-treated by rapid recurrent thermal annealing (RRTA) method

摘要

Based on the electric dipole transition model of four energy levels, the frequency spectrum of Faraday angle in blue and violet light ranges has been analyzed. According to theoretical results, the optimized stoichiometric compositions is BiyDy3-yFe5-xAlxO12 with x=0.8 ～ 1.2 and y=1.0～1.96., and then high quality BiAlDyIG thin films have been prepared by a sol-gel method and post-treated by RRTA method. The effects of RRTA on Faraday angle of the films have been studied in detailed, a maximum Faraday angle of 4.9degree in the 450nm thickness film (Bi1.96Dy1.04Fe4AlO12) was obtained, which is about 2.0degree larger than that of the common thermal annealed (CTA) samples. These results are potentially helpful to improve the recording density and signal-noise-ratio of magneto-optical disk.