The Growth and Magneto-optical Properties of Large Size Single-crystal Thick TmBiIG Films from Lead-free Flux by LPE Technology

摘要

In this paper, we prepared the 3-inch magneto-optical (MO) single crystal garnet film with the composition of (TmBi)_3(FeGa)_5O_(12) by Liquid phase epitaxy (LPE) from lead-free flux. The MOgarnet films are grown on Gd_3Ga_5O_(12) (GGG (111)) substrate because of the good lattice match between the film and the substrate. In our experiment, we choose the Bi_2O_3 as the fluxing agent not frequently-used PbO because the latter is poisonous and brings negative impact to the growth film. The good films with low defects, mirror surface, high Faraday Rotation angle(FR) and big thickness have been obtained by optimizing the flux ratio and LPE technological parameters. The thickness of the film can reach about 50-60 micrometers in 3-inch GGG substrate. The optimal growth rate is 0.85 … 0.95 μm/min, and mismatch between TmBiIG film and GGG substrate gets its smallest and good magnetic and MO properties have been obtained with this growth rated. The biggest FR is 0.54 degree/ μm as the external magnetic field is as small as 25 Oe. The Ms and Hc of TmBilG film reaches its biggest and smallest value as the growth rate is 0.92 μm/min, respectively, and the value is 50 emu/cm~3 and 5 Oe.