Effect of Si4+ doping on the microstructure and magneto-optical properties of TAG transparent ceramics

The Si-doped TAG transparent ceramics were fabricated successfully using solid state reaction and vacuum sintering. Influence of Si4+ doping (0-0.6at%) on microstructure and magneto-optical properties of TAG ceramics was investigated. It was found that doping Si4+ into TAG was conductive to remove the porosity and improve the optical quality of TAG ceramics significantly. The TAG ceramic sample with 0.2at% Si4+ doping (S1) has the highest transmittance among the samples, which can reach 80% in the 1000-1500nm region and it also has the largest grain size of 42.9μm. No pores and impurity phase were found within the grains or along the boundary. The Verdet constant of sample S1 was measured and the value at 633nm was 173.46 rad/Tm, which was similar with that of pure TAG crystal and 29% higher than that of TGG crystal.