PWO晶体生长与完整性研究  

Analysis on Growth and Integrity of PWO Crystal

作　　者：刘景和[1] 王英伟[1] 孙晶[1] 李建利[1] 张亮[1] 

机构地区：[1]长春光学精密机械学院,长春130022

出　　处：《仪器仪表学报》2002年第z3期141-143,共3页Chinese Journal of Scientific Instrument

摘　　要：用 Cz法生长尺寸为Φ 2 5× 30 mm的高质量的 PWO晶体 ,设计了合理的工艺参数 ,总结了影响 PWO晶体完整性的因素。发现晶体开裂有四种形式 :横向层状似的断裂 ;纵向长裂纹 ;沿解理面 (10 1)或 (0 11)面开裂 ;无规则碎裂。通过结构分析认为 ,结构应力导致晶体的无规则碎裂 ,通过选用高纯原料 ,结构完整的籽晶等方法可减小结构应力。并认为晶体开裂的主要因素是热应力而引起的。经过大量实验表明 ,热应力引起的开裂除了沿解理面方向外 ,还由于各方向上热膨胀系数不同 ,而表现为横向层状的断裂 (偏 C轴方向生长 )和纵向裂纹 (偏 a轴方向生长 )的两种形式。可通过设计合理而稳定的温场 ,选择最佳工艺参数及退火处理等方法 ,减少热应力而引起的晶体开裂。The PWO crystal was grown by Cz method,designed rational processing coefficients,summarized the factors affect the integrity of the PWO crystal. We found that causing of crystal cracking was as four follows:lateral crack;longitudinal length crack; along the cleavage place ((101) place or (011)place) crack;random fracture crack. Factor of crystal cracking is caused by thermal stress mainly. Structure analysis shows that structure stress can be decreased through select high purity raw material. Through a lot of experiments we have known that crystal cracking of thermal stress included not only along cleavage place crack but also lateral stratum crack (growth of C direction) and longitudinal length crack (a-axial direction growth) which was caused by dissimilar coefficient of expansion in all directions. During designing stable temperature field and selecting rational technology parameter and annealing process,perfect crystal was grown.

关 键 词：PWO晶体 Cz法 结构应力 热应力 晶体开裂 

分 类 号：TP2[自动化与计算机技术—检测技术与自动化装置]