State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, PR China.
Dalton Trans. 2010 Feb 14;39(6):1546-51. doi: 10.1039/b916893a. Epub 2009 Dec 15.
A new eulytite-like orthophosphate Pb(3)Bi(PO(4))(3), was synthesized by the high temperature solution growth (HTSG) method and characterized by X-ray single crystal diffraction, powder diffraction and electron microscopy. It crystallizes in the acentric cubic space group (I4[combining macron]3d). The pure-phase powders of Pb(3)Bi(PO(4))(3), Ba(3)La(PO(4))(3) and Ba(3)Bi(PO(4))(3) were also prepared by the high temperature solid reaction method. Second harmonic generation (SHG) measurements revealed that the optical response signals of Pb(3)Bi(PO(4))(3) and Ba(3)Bi(PO(4))(3) are about 3.0 and 0.5 times that of KH(2)PO(4) (KDP), respectively, and both are phase-matchable. The SHG signal of Ba(3)La(PO(4))(3) is very weak. Our studies indicate that the enhancement of the nonlinear optical response is mainly due to the contribution from the irregular PbO(6) and BiO(6) octahedra due to the 6s(2) lone electron-pair stereochemical activity in eulytite-like orthophosphates. Additionally, the calculated band structure and density of states also provide evidence that the charge transfers within irregular octahedral of Pb/BiO(6) make a significant contribution to the nonlinear optical response.
一种新的钙钛矿型磷酸盐 Pb(3)Bi(PO(4))(3)，通过高温溶液生长法（HTSG）合成，并通过 X 射线单晶衍射、粉末衍射和电子显微镜进行了表征。它结晶于非中心立方空间群（I4[combining macron]3d）。采用高温固相反应法还制备了纯相 Pb(3)Bi(PO(4))(3)、Ba(3)La(PO(4))(3)和 Ba(3)Bi(PO(4))(3)粉末。二次谐波产生（SHG）测量表明，Pb(3)Bi(PO(4))(3)和 Ba(3)Bi(PO(4))(3)的光学响应信号分别约为 KH(2)PO(4)（KDP）的 3.0 倍和 0.5 倍，两者均为相位匹配。Ba(3)La(PO(4))(3)的 SHG 信号非常弱。我们的研究表明，非线性光学响应的增强主要归因于不规则 PbO(6)和 BiO(6)八面体的贡献，这归因于钙钛矿型磷酸盐中不规则 Pb/BiO(6)的 6s(2)孤对电子的立体化学活性。此外，计算出的能带结构和态密度也证明了不规则八面体内部的电荷转移对非线性光学响应有重要贡献。
