Yb:KGd(WO_4)_2激光晶体结构与振动光谱

Structure and Vibration Spectrum of Laser Crystal Yb:KGd(WO_4)_2

用顶部籽晶提拉法,以K2W2O7为助溶剂,生长Yb:KGd(WO4)2激光晶体.经热重. 差热分析,确定晶体熔点为1086℃,相变温度为1021℃晶体结构分析确定Yb:KGW(WO4)2 晶体由WO6八面体连接而成,WO6八面体是由(WOOW)双氧桥及(WOW)单氧桥构成. 晶体粉末样品室温下的红外及拉曼光谱测试,确定WO42-、双氧桥及单氧桥的振动范围,并对其进行了归属.X射线粉末衍射测试,验证所生长的晶体为β-Yb:KGd(WO4)2.

The selection of the flux and the design of the proper processes are the key factor for the growth of Yb：KGd（WO4）2 laser crystal. Yb：KGd（WO4）2 crystal was grown by the Top Seeded Solvent Growth （TSSG） method using K2W2O7 as a suitable flux. On the base of TG-DTA, the crystal has two obvious absorption peaks at 1086℃ and 1021℃, its melting point is 1086℃, phase transition temperature from tetragonal to monoclinic is 1021℃. The Yb：KGd（WO4）2 crystal consists of WO6 octahedra which consists of WOOW double oxygen bridges and WOW single bridges. IR and Raman spectra show the atom group WO4^2- flex vibration at 436 cm^-1 and atom group WO4^2- bend vibration at 740-925cm^-1, WOOW double oxygen bridge vibration at 903, 765, 684, 438, 498 and 297cm^-1, WOW single bridges vibration at 808, 526 and 232cm^-1. Analyzing on the X-ray diffraction spectrum of Yb：KGd（WO4）2 crystal powder sample, we can conclude that the β-Yb：KGd（WO4）2 crystal is of a monoclinic system, and C2/c space group.