稀土掺杂LiYF4晶体生长研究
毕业论文关键词：LiYF4晶体；坩埚下降法；稀土；掺杂
Abstract
In this paper, we collected the literatures about LiYF4 crystals and presented the growth
techniques for crystal growth of LiYF4 crystals, including vertical Bridgman method,
Czochralski method, μ-PD method. The vertical Bridgman method was introduced in detail. In
the experiment, we adopt in the process of the synthesis of LiF, YF3, NdF3, PrF3, EuF3
polycrystalline raw materials, according to the ratio of raw materials, ingredients in the
different doping ratio using multiple platinum crucible, grow in air atmosphere, in the absence
of any deoxidizer has many kinds of rare earth doped LiYF4 crystals.The furnace temperature
was controlled by DWT-702 with an accuracy of ±0.5℃. As-grown crystal showed transparent
in the early stage and opaque in the end stage, which may be caused by the impurity
accumulation. As-grown crystal was oriented, cut and polished into slices of 1mm thickness
for measurement. Powder X-ray diffractometer was measured by Rigaku Rigaku D/max
2500V/PC type) and compared with LiYF4 standard card.
Keywords: LiYF4 crystals; Bridgman crystal growth; Rare earth; Doping
目录
1 绪论. 1
1.1 氟化钇锂晶体国内外研究现状1
1.1.1 氟化钇锂晶体.1
1.1.2 稀土掺杂氟化钇锂晶体.2
1.1.3 氟化钇锂晶体的应用.5
1.2 氟化钇锂晶体生长方法6
1.2.1 坩埚下降法.6
1.2.2 提拉法.8
1.2.3 μ-PD法9
1.3 选题的目的和意义10
2 实验方法. 12
2.1 实验试剂12
2.2 实验步骤13
2.2.1 原料的氟化.13
2.2.2 晶体生长.13
2.3 晶体的加工14
2.3.1 晶体的切割.14
2.3.2 晶体的研磨.14
2.3.3 晶体的抛光.15
2.4 晶体的测试15
3 结果讨论与分析. 17
3.1 配料计算17
3.2 晶体的生长17
3.3 晶体 XRD测试19
4 结论. 22
参考文献. 23
致谢25
1 绪论
1.1氟化钇锂晶体国内外研究现状
1.1.1 氟化钇锂晶体
氟化钇锂晶体是无色透明的晶体，属于四方晶系白钨矿结构（如图 1.1）的
正光性单轴晶体，晶格常数值 a=5.26 0.03A，c=10.94 0.03A，空间群为
4 ，对称轴为 4/m，晶体结构如图 1.2 所示，每个晶胞有四个LiYF4，每
个 Li+被空间等价的四个 F-包围，构成 LiYF4四面体，每个 Y3+与相邻的八个 F-
形成对称性为S4的 YF8多面体，每个Y3+周围有四个距离相等的次近邻 Li+，每个 Li
+周围有四个距离相等的次近邻 Y3+，即由 Y3+和 Li+构成亚晶格为两个相互渗透的类金刚石网。1.1.2 稀土掺杂氟化钇锂晶体
从70 年代开始，掺稀土元素的 LiYF4晶体，尤其是掺 Nd：LiYF4晶体，在
激光领域得到了极大关注，从闪光灯泵浦到LD 泵浦，均已得到了广泛的应用。