大截面NaCl晶体的生长和性能

Study on Growth and Properties of Large-sized NaCl Crystal

采用电阻加热Czochralski法和坩埚底部补偿技术,在优化温场和工艺参数后,生长出了φ130 mm×100 mm的NaCl单晶.XRD分析表明,NaCl晶体为立方晶系,晶格常数为a=0.5640_(2) nm.晶体的透光性能测试表明:厚度4 mm的样品的透过率大于91.5%;晶体的Virckers硬度为21.52 kg/mm^(2),硬度系数为1.672,证明NaCl晶体是一种软质材料;晶体的光学均匀性随着位错密度的增加而降低;热释光发光(TL)曲线表明,NaCl晶体的发光峰位于74.35℃和221.14℃,后者的发光强度是前者的5倍以上,表明NaCl晶体是一种可用于剂量测定和红外领域的优质材料.

After the optimization of temperature field and the process parameters,the NaCl single crystal with the size of φ130 mm×100 mmwas grown by the resistance heating Czochralski(Cz)method and the bottom of the crucible compensation technology.XRD analysis shows that the NaCl crystal is a cubic system with a lattice constant of a=0.56402nm.The transmittance test of the crystal suggests that the transmittance of a sample with a thickness of 4 mm is greater than 91.5%.The vickers hardness of the crystal is 21.52 kg/mm^(2),and the hardness coefficient is 1.672,which proves that NaCl crystal is a soft material.The optical uniformity of the crystal decreases with the dislocation density increase.The thermoluminescence luminescence(TL)curve shows that the thermoluminescence peaks of the crystal are located at 74.35 and 221.14℃,respectively,and the luminous intensity of the latter is more than 5 times that of the former.The results show that NaCl crystal is a high-quality material,which can be used in dosimetry and infrared fields.