K_2Al_2B_2O_7晶体的热学性质研究  

Investigation on the Thermal Properties of K_2Al_2B_2O_7 Crystal

作　　者：张承乾[1] 王继扬[1] 胡晓波[1] 张怀金[1] 

机构地区：[1]山东大学晶体材料国家重点实验室,济南250100

出　　处：《人工晶体学报》2005年第5期786-789,共4页Journal of Synthetic Crystals

基　　金：国家自然科学基金(No.50372027)资助

摘　　要：K2Al2B2O7(KABO)晶体是近年发现的一种有应用前景的深紫外非线性光学晶体,也是目前唯一一种可以生长出大尺寸单晶的BO3基团非线性光学晶体.KABO有可能用于固态激光器的266nm及193nm高功率输出.本文对该晶体的物理化学性质及热学性质进行了研究,KABO晶体不潮解,不溶于水、酒精等溶剂,可溶于盐酸,硝酸和磷酸等强酸;测得莫氏硬度为5.5～6.5,用浮力法测得其密度为2.47g/cm3;用差热分析(DTA)方法测量其熔点为1109.7℃.用热重分析(TGA)方法结合分解产物的粉末X射线衍射(XRD)分析,确定KABO在900℃以上开始分解,分解产物主要为KAl11O17和K2Al24O37;用热机械分析仪测量了其热膨胀系数,沿物理学轴X、Y、Z方向分别为8.4×10-6/K、7.7×10-6/K、1.65×10-5/K.在室温至300℃温度范围内测量了KABO晶体的比热变化,比热随温度的升高线性增大.在47.6℃和294.6℃时比热分别为1.0084J/g℃与1.39J/g℃.K2Al2B2O7 （KABO） crystal is a promising ultra-violet （UV） nonlinear optical （NLO） crystal. It is the only crystal that can be grown in large size at present in the family of NLO crystals based on BO3 anionic group. High power solid-state lasers at 266nm and 193nm with KABO devices are expected to obtained. Its physics-chemical properties were investigated in this paper. The KABO crystal is nonhygroscopic. It is stable in the solvents such as water and alcohol, etc. It can be dissolved in acids such as HC1, HNO3 and H3PO4, etc but not alkali such as KOH and NaOH. Its hardness is 5.5-6.5. Its density was determined to be 2.47g/cm^3 by using a buoyancy method. The melting point was observed to be 1109.7℃ in DTA measurement. Its thermal chemical stability was investigated with a TGA method combined with XRD analyzing of the decomposed products. It is determined that KABO decomposes above 900℃. The remaining products are mainly KAl11O17 and K2Al24O37. Its thermal expansion coefficients were measured with a thermal mechanical analyzer. They are 8.4 ×10^-6/K,7.7×10^-6/K and 1.65×10^-5/K along its X, Y,Z-axis respectively. Relations of its specific heat to temperature were measured from room temperature to 300℃ with a DSC 822^e differential scanning calorimeter. The specific heat increases linearly in the range of experimental temperature. 1. 0084J/g℃ and 1.39J/g℃ of its specific heat were measured when the temperature is at 47.6℃ and 294.6℃ respectively.

关 键 词：硼酸铝钾 热学性质 非线性光学晶体 

分 类 号：O782[理学—晶体学]