摘要：中红外非线性光学晶体在民用和军事领域都有重要的应用。现有的中红外非线性光学晶体材料包括AgGaS2，AgGaSe2，ZnGeP2和LiBC2（B=Al,Ga,In;C=S,Se,Te），虽然它们都各具优点，但却也都有其局限性，如由于低的激光损伤阈值，使得它们在中红外区域中的使用均存在一定的限制。所以高激光损伤阈值的中红外非线性光学晶体的探索成了材料科学研究的热点。本实验依据结构选型→固相合成→晶体生长→性能测试的研究方法，采用固相二次烧结的方法合成了Pb2(O1-xSx)Cl2(POSC)多晶原料，并利用该多晶料使用自发成核的方式成功生长出了POSC晶体。通过合成样品的X射线衍射分析，找到了结晶度较好的Pb2(O0.8S0.2)Cl2晶体。通过热稳定性试验得知POSC晶体热稳定性较好，熔点为506℃。我们还对POSC多晶原料进行了漫反射和扫描电镜（SEM）分析，通过计算得知POSC晶体为间接带隙半导体，SEM分析结果表明合成的POSC多晶原料的粒径大小在1~2μm之间。71788

毕业论文关键词：POSC多晶；固相反应；晶体生长；自发成核

Synthesis and Characterization of

Infrared POSC Crystal Materials

Abstract： Infrared non-linear optical crystals in both military and civilian aspects have important applications.

However, the conventional mid-infrared nonlinear optical crystal materials include AgGaS2, AgGaSe2, ZnGeP2 and LiBC2 (B = Al, Ga, In; C = S, Se, Te ) Have their own advantages, but they also have their limitations. Due to their low laser damage thresholds, their use in the mid-infrared region has some limitations. Therefore, the exploration of mid-infrared nonlinear optical crystals with high laser damage threshold has become a hotspot in laser technology research.

Pb2(O1-xSx)Cl2(POSC)polycrystalline raw materials were synthesized by solid-phase secondary sintering based on the structure selection → solid phase synthesis → crystal growth → performance test. Spontaneous nucleation of the successful growth of the POSC crystal. The crystal of Pb2(O0.8S0.2)Cl2 with better crystallinity was found by X-ray diffraction analysis of the synthesized samples. Through the thermal stability test that POSC crystal thermal stability is better, the melting point of 506 ℃. The results show that the size of the synthesized POSC polycrystalline raw materials is 1 ~ 2μm, and the results show that the POSC polycrystalline raw materials are characterized by diffuse reflection and scanning electron microscopy (SEM) analysis. between.

KeyWords: POSC polycrystalline；Solid phase reaction；Crystal growth；Spontaneous nucleation  

目  录

1 引言 1

1.1 非线性光学晶体的研究历史 1

1.2 激光技术对非线性光学晶体的基本要求 2

1.3 非线性光学晶体的研究现状 3

1.4 POSC中红外非线性红外光学材料的探索 4

2 POSC多晶料的合成 5

2.1 多晶料的合成方法（固相反应法） 5

2.2 实验原理 5

2.3 实验所需化学试剂 7

2.4 实验所用仪器 8

2.5 POSC中S元素的掺杂比例 9

2.6 实验步骤 10

3 POSC晶体的生长 13

3.1 自发成核的原理 13

3.2 自发成核生长POSC晶体 14

3.3 自发成核合成的POSC晶体