光散射学报, 2004, 16 (1): 21, 网络出版: 2006-04-20
硫氰酸镉锌晶体的振动光谱和结构
Vibrational Spectra and Structure of ZnCd(SCN)4 Single Crystal
非线性光学晶体 硫氰酸镉锌 拉曼光谱 分子轨道理论 Nonlinear optical crystal materials Zinc cadmium thiocyanate Raman spectra Molecular Orbital theory
摘要
本文通过对硫氰酸镉锌(ZnCd(SCN)4,简称ZCTC)晶体的群论、拉曼光谱分析和理论计算发现,对于具有I4对称性的ZCTC,在结构中具有ZnN4、CdS4畸变四面体,ZnN4与CdS4由电子桥-N=C=S-联结构成三维骨架的空间无限延伸的结构网络,畸变四面体产生的偶极矩通过电子桥传递,微观偶极矩通过电子桥-N=C=S-相互叠加,且方向一致,从而使宏观晶体材料显示出大的非线性效应.
Abstract
The vibrational spectra of the zinc cadmium thiocyanate (ZCTC) single crystal are studied by Raman spectroscopy and ab initio calculation with the Molecular Orbital (MO) theory using a GAUSSIAN 98 program. Agreement is achieved between the vibrational frequencies predicted by the theory and those observed in Raman scattering experiments. The results show that the characteristic vibrational modes of ZCTC crystal arise mainly from the internal vibrations of the SCN, Zn(NCS)_4, and Cd(SCN)_4 clusters. The three-dimensional network structure of ZCTC crystal is identified, and the highly optical nonlinearities of the crystals are chiefly ascribed to the distorted Zn(NCS)_4 and Cd(SCN)_4 tetrahedra and the conjugated charge-transfer (-Zn-NCS-Cd-) bridges that connect all the distorted tetrahedra together.
刘伟良, 夏海瑞, 王新强, 许东. 硫氰酸镉锌晶体的振动光谱和结构[J]. 光散射学报, 2004, 16(1): 21. 刘伟良, 夏海瑞, 王新强, 许东. Vibrational Spectra and Structure of ZnCd(SCN)4 Single Crystal[J]. The Journal of Light Scattering, 2004, 16(1): 21.
PDF全文
