Ybx：KY1-x(WO4)2晶体生长及振动光谱研究

Study on Crystal Growth and Vibrational Spectra of Yb_x:KY_(1-x)(WO_4)_2

采用TSSG法生长出Ybx:KY1-xW(x=0.05)和KYbW晶体,并对两者的结构和光谱性能进行了比较。工艺参数为,转速10～15r.min-1,拉速1～2mm.d-1,生长周期10～15d,降温生长速率0.05～0.1℃.h-1,降温速率20℃.h-1。XRD分析表明两者均为低温相的β-KYW结构,两种晶体的晶格常数分别为a1=1.063nm,b1=1.034nm,c1=0.755nm,β1=130.75°,Z1=4和a2=1.061nm,b2=1.029nm,c2=0.749nm,β2=130.65°,Z2=4。测试了红外及拉曼光谱,Ybx:KY1-xW(x=0.05)样品在925,891,840,777,749cm-1具有较强的红外吸收峰,是由WO4原子基团伸缩振动引起的;KYbW样品在484和437cm-1处具有较强的红外吸收峰,反映了WO4原子基团的弯曲振动。分析了晶体的振动模式,认为两种晶体有较强的拉曼活性,钨氧双桥键WOOW和单桥键WOW基团的振动在200～1000cm-1范围内,对峰值与相应的振动进行了指认。

Ybx ： KY1-xW（x=0.05）and KYbW crystals were grown by TSSG method. Both of the structure and spectral properties were compared. The condition for the crystal growth is： the rotation rate 10-15 r· min^-1 , the pulling speed 1-2 mm ·d^-1 , the growing period 10-15 d, cooling growing speed 0.05-0. 1℃ · h^-1 , and the cooling speed 20℃· h^-1. X-ray powder diffraction analysis was performed for the crystal powder. They belong to β-KYW structure with low thermal phase. The cell pararneters of the two crystals were calculated, and they are respectively a1 = 1. 063 nm, b1=1. 034 nm, c1 =0. 755 nm, β1 = 130. 75°, Z1 =4 and a2=1. 061 nm, N =1. 029 nm, c2 =0. 749 nm, β2=130. 65° and Z2 =4. The infrared spectrum and Raman spectrum of crystal were measured. The sample of Ybx ： KY1-xW（x=0.05） had stronger infrared absorption peaks at 925, 891, 840, 777 and 749 cm^-1 , which were caused by stretching vibration. The sample of KYW had stronger infrared absorption peaks at 484 and 437 cm^-1 caused by bending vibration. The vibration modes were analysed and vibrational frequencies of vibratory activity was assigned. The two crystals had strong Rarnan activity. The vibration of WOOW and WOW exists from 200 to 1 000 cm^-1.