Improved Edge-Defined Film-Fed Growth of Incongruent-Melting Tb₃Al₅O₁₂ Crystal with High Magneto-Optical and Thermal Performances

Abstract

Vis–NIR magneto-optical crystals are the key materials in the fields of optical fiber communication, smart grids, optical fiber lasers, and so on. In this paper, the incongruent-melting Tb3Al5O12 (TAG) single crystals with centimeter size and high quality were grown rapidly by an EFG method with the suitable design of a melt component. The effects of the sintering temperature of polycrystalline materials, the melt component, and the growth rate on the crystal quality were discussed in detail. The Verdet constants, hardness, thermal expansion coefficients, specific heat capacities, and thermal diffusivities of TAG crystal were measured. The results show that the Verdet constant of the TAG crystal is 8–30% larger than those of Tb3Sc2Al3O12 (TSAG) and Tb3Ga5O12 (TGG) crystals. Additionally, the TAG crystal also has the advantage in both thermal conductivity and hardness. Therefore, the TAG crystal has good comprehensive performance and thus has important application prospects.