新型磁光晶体Tb3R2Al3O12的生长及磁光本征研究

The relation between rare earth ions and magneto-optical property was found Vleck and Hebb et al. which is published in Phys Rew at 1934. Based on the theory, a series of magneto-optical materials, such as Ce3+ doped YIG crystal, Tb3Ga5O12(TGG) crystal and Tb paramagnetism glass etc., were found and widely applied in lasers. The novel type Tb garnet magneto-optical crystals have been found and grown since 1990s. The magneto-optical property can be improved and adjusted with various compositions of metal element in the dodecahedron site. Tb3R2Al3O12 (R-Sc，Lu，Gd, etc.) will be investigated in this project. High quality In the project, Tb3R2Al3O12 crystals are grown; their magneto-optical and Opto-magnetism properties are investigated. The relation between magneto-optical, opto-magnetism properties and the radius, magnetic moment etc. of R ions will be found. The relation between Faraday Effect and Inverse Faraday effect, the nature of the magneto-optical response in paramagnetism material will be probed. The achievement is helpful to realizing artificial regulation on the material physical property in material design; meanwhile, it can provide basic theory for searching novel magneto-optical crystal in the wavelength of visible light.

Vleck和Hebb等人关于磁光性能的理论公式，揭示了稀土离子与材料磁光性能之间的关系。在该理论的指导下，Ce3+掺杂YIG晶体、Tb3Ga5O12(TGG)晶体和部分Tb基顺磁玻璃等一系列磁光材料被发现和广泛应用。上世纪九十年代以来，中外学者先后开展了Tb基石榴石新型磁光晶体的生长，发现改变石榴石结构十二面体配位的金属元素组分和含量，可以提高晶体的磁光性能。本项目选择Tb3R2Al3O12 (R为Sc，Lu，Gd等金属元素)为研究对象，首先生长出高质量的晶体材料，开展其磁光和光磁性能的研究；进而系统研究由于石榴石结构中十二面体配位的金属离子半径、磁矩大小的不同，对材料磁光及光磁性能的影响；探索顺磁性材料的磁光本征，以及法拉第效应与逆法拉第效应之间的关系。从而在材料设计层面，实现对材料物理性能的人工调控，为探索可见光波段的新型磁光晶体材料提供重要的技术积累和基础研究资料。

TGG单晶具有大的磁光常数、低的光损失、高热导性和高激光损伤阈值， 广泛应用于YAG 、掺Ti蓝宝石等多级放大、环型、种子注入激光器中，是用于制作法拉第旋光器与隔离器的最佳磁光材料。本课题选择石榴石结构的Tb3R2Al3O12 (在石榴石结构中，Tb占十二面体位置，R占八面体位置，Al占四面体位置)为研究对象，希望通过Tb位和R位的掺杂，研究不同掺杂对磁光性能的影响，并得到磁光性能更优异的新型磁光材料。Lu掺杂的Tb2.2Lu0.8A15O12晶体具有高光透过率、高热导率，有很高的潜在应用价值。通过光学浮区法对TSAG晶体进行生长，Verdet常数为170 rad/m/T左右，明显高于TGG晶体，对其磁性的研究表明，磁性上表现出的差异可以与Verdet常数表现出的差异相对应，这一结论证明在同一体系中，可以通过磁化率的大小比较材料费尔德常数的大小。