MgF2作为镁离子内扩散LiNbO3单晶扩散源的研究

利用ＭｇＦ₂作为扩散源进行镁离子内扩散ＬｉＮＯ₃单晶基片的研究．经电子探针显微镜分析表明，镁的扩散层镁离子浓度分布具有近似半抛物形和阶跃形分布，并得到镁的激活能为１０４ＫＪ／mol.X射线衍射分析发现，当镁离子内扩散超过一定程度时，在镁的扩散层出现具有ＬｉＮｂ₃Ｏ₈的物相结构，并发现该物相结构的出现与ＬｉＮＯ₃体内锂离子的外扩散和扩散表面氟离子的存在有关．由扫描电子显微镜观察到氟离子以ＬｉＦ的形式出现，并随着扩散程度的增大，挥发和脱离开扩散层表面． 关键词：

A STUDY OF MgF2 AS A DIFFUSION SOURCE FOR Mg-ION INDIFFUSION LITHIUM NIOBATE SINGLE CRYSTAL

A study of the Mg-ion indiffusion of lithium niobate single crystal substrate is made by MgF₂ as a diffusion source. By means of electron probe microanalysis, the Mg-ion concentra tion of the Mg diffused layer is obtained, which is approximately a half parabolic and step profiles. The activation energy of Mg-ion indiffusion is 104 kJ/mol. It is found by X-ray diffraction analysis that in the Mg diffused layer LiNb₃O₈ compound appears with Mg-ion in diffusion beyond a certain extent. The appearance of LiNb₃O₈ compound is related to the Li ion outdiffusion from the bulk of lithium niobate and existence of a great deal of F-ion at the diffused surface. It is observed by scanning electron microscopy that the F-ion is in the form of LiF and LiF will go away from the surface of the Mg diffused layer with increasing of Mg ion indiffusion degree.