大尺寸Nd^(3+):GGG激光晶体的单胞参数计算和组分分析

Lattice Parameters Calculation and Component Analysis of Large-size Nd^(3+):GGG Laser Crystal

采用提拉法生长了直径为136 mm的Nd3+:GGG单晶,通过X射线衍射和X射线荧光对晶体的结构、成分沿生长方向和径向的变化进行了测试分析。结果表明单胞晶格参数沿晶体的生长方向和径向均逐步变大,平均变化率分别为3.1×10-6/mm、1.3×10-5/mm;沿着晶体的生长方向,Nd和Gd组分按指数函数规律逐步增加,而Ga组分则按高斯函数逐渐减小。沿晶体径向从内到外,Nd、Gd组分按线性规律逐渐增大,其变化率分别为0.0014 at%/mm、0.00924 at%/mm,Ga组分则按线性规律减小,变化率为-0.0117 at%/mm。这些变化主要是由于Nd3+的分凝效应、Ga挥发所导致。

Nd3＋∶GGG single crystal with diameter of 136 mm was grown by Czochralski method.The structure and component variation along crystal growth direction and radial direction were measured and analyzed by X-ray diffraction（XRD） and X-ray fluorescence（XRF）,respectively.The results indicate that the lattice parameters increase gradually along crystal growth direction and radial direction,and mean variance ratio are 3.1×10^-6 /mm、1.3×10^-5 /mm,respectively.Along the crystal growth direction,the components of Nd and Gd increase by exponential functions,and Ga decreases by Gauss function.In radial direction from interior to exterior,the components of Nd and Gd increase by linear rule,whose variance ratio are 0.0014 at%/mm and 0.00924 at%/mm,Ga decreases by linear rule whose variance ratio is-0.0117 at%/mm.These variances are from the segregation effect of Nd3＋ and volatilization of Ga.