铁电单晶0.62Pb(Mg_(1/3)Nb_(2/3))O_3-0.38PbTiO_3折射率的研究  

Study on principal refractive indices of the ferroelectric single crystal 0.62Pb(Mg_(1/3)Nb_(2/3))O_3-0.38PbTiO_3

作　　者：万新明[1] 贺天厚[1] 林迪[1] 徐海清[1] 罗豪甦[1] 

机构地区：[1]中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海201800

出　　处：《物理学报》2003年第9期2319-2323,共5页Acta Physica Sinica

基　　金：国家 8 63高技术研究项目 (批准号 :2 0 0 2AA3 2 5 13 0 );国家自然科学基金(批准号 :5 0 2 72 0 75 )资助的课题~~

摘　　要：用最小偏向角法在 2 0℃下精确测量了 0 6 2Pb(Mg1 3Nb2 3)O3 0 38PbTiO3( 0 6 2PMN 0 38PT)单晶的折射率 ,给出了该温度下折射率色散的Sellmeier方程 .研究了能带结构与折射率的关系 ,计算了样品的Sellmeier光学系数 :对no,E0 =5 5 0eV ,λ0 =0 2 2 6 μm ,S0 =1 0 0 4× 10 1 4m- 2 ,Ed =2 8 10eV ;对ne,E0 =5 5 7eV ,λ0 =0 2 2 3μm ,S0 =1 0 17×10 1 4m- 2 ,Ed=2 8 10eV .ABO3型钙钛矿材料中 ,BO6 八面体基元决定了晶体的能带结构 。The refractive indices and their dispersions in 0.62Pb(Mg1/3Nb2/3)O-3-0.38PbTiO(3) (PMNT62/38) single crystals were accurately measured with the minimum deviation method at 20degreesC. The parameters of modified Sellmeier's equation for both n(o) and n(e) are obtained. We relate the refractive indices to energy-band structure of oxygen-octahedron ferroelectrics and the Sellmeier optical coefficients, E-0 = 5.50eV, lambda(0) = 0.226mum, S-0 = 1.004 x 10(14) m(-2) and E-d = 28.10eV for n(0) and E-0 = 5.57eV, lambda(0) = 0.223mum, S-0 = 1.017 x 10(14) m(-2) and E-d = 28.10eV for n(e) were obtained through fitting the single-term oscillator equation. For materials with ABO(3) perovskite structure, the octahedral BO6 unit governs the lower lying conduction bands and the upper valence bands and makes a substantial contribution to the refractive indices.

关 键 词：铁电单晶 0.62Pb(Mg1/3Nb2/3)O3-0.38PbTiO3 折射率 能带结构 Sellmeier光学系数 色散方程 

分 类 号：O734[理学—晶体学]