近化学计量比铌酸锂晶体组分过冷与临界生长速率研究

本文在用双坩埚提拉法生长近化学计量比LiNbO3晶体的过程中观察到了组分过冷的实验数据,同时根据Tiller-Chalmers稳定性判据公式半定量计算了近化学计量比LiNbO3晶体临界生长速率的理论值,得到一般电阻加热双坩埚提拉法生长近化学计量比LiNbO3晶体的临界生长速率为0.1mm/h数量级.通过临界生长速率解释了一系列晶体生长的实验结果.提出了一些工艺措施来避免组分过冷,根据这些工艺获得了无包裹体的近化学计量比LiNbO3晶体.

Investigation of Constitutional Supercooling and Critical Growth Rate of Stoichiometric Lithium Niobate Crystal

The direct experimental data of constitutional supercooling during the crystal growth of nearstoichiometric lithium niobate by double crucible Czochralski method were observed and the theoretical issues of the critical rate were treated based on the stability criterion equation. The critical growth rate was calculated and applied to explain the experimental results of crystal growth. Several critical points of growth process were proposed to grow inclusion-free near-stoichiometric lithium niobate crystals avoiding constitutional supercooling.