非对称扩散工艺制备近化学计量比钽酸锂晶体的研究

Preparation of Near Stoichiometric Lithium Tantalate Crystal by Asymmetric Diffusion Technique

利用气相平衡输运法制备的近化学计量比钽酸锂晶体质量好,制备工艺简单,但受固体扩散速率低的影响,该方法较难制备大厚度晶体。本文基于钽酸锂晶体的扩散机制,采用待扩散晶片一侧为富锂气氛,另一侧为同成分气氛的非对称扩散工艺,对钽酸锂晶体进行了扩散处理,并对组分和畴反转电场进行表征。结果表明,非对称扩散工艺为反位钽离子的扩散提供了通道,提高了晶体中反位钽离子和锂离子的扩散速率,有利于制备大厚度近化学计量比钽酸锂晶体。

Vapor equilibrium transport method is used to prepare near stoichiometric lithium tantalate crystals with high quality.However,it is difficult to prepare large-thickness crystals by this method due to its low solid diffusion rate.In this paper,based on the diffusion mechanism of lithium tantalate crystal,the diffusion of lithium tantalate crystal was carried out by asymmetric diffusion process with lithium rich atmosphere on one side of the wafer and congruent composition atmosphere on the other side.The composition and domain inversion field were characterized.The results show that the asymmetric diffusion technique provides a channel for the diffusion of anti-tantalum ion and increases the diffusion rate of anti-tantalum ion and lithium ion in the crystal,which is beneficial to the preparation of large-thickness near stoichiometric lithium tantalate crystal.