红外与毫米波学报, 2015, 34 (4): 442, 网络出版: 2015-10-22
Pb(Mg1/3Nb2/3)O3-0.3PbTiO3单晶紫外可见近红外光学性质
UV-Vis-NIR optical properties of Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 single crystal
铁电单晶 透射光谱 反射光谱 禁带宽度 光学常数 ferroelectric single crystal transmittance and reflectance spectra opitcal band gap optical constant
摘要
通过温度依赖的透射和反射光谱研究了在准同型相界附近的Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-0.3PT)单晶光学性质.这种禁带宽度随温度范围不同变化规律不同现象, 揭示了PMN-PT单晶温度依赖的复杂相结构.禁带宽度Eg在303 K是3.25 eV, 临界点Ea是3.93 eV, 临界点Eb是4.65 eV, 它们随着温度的上升而下降, 在453 K禁带宽度Eg是3.05 eV, 临界点Ea是3.57 eV, 临界点Eb是4.56 eV.这三个跃迁能量Eg、Ea、Eb分别对应从O 2p到Ti d、Ni d、Pb 6p轨道跃迁.它们随温度上升而下降的变化规律可以用晶格热膨胀和电子声子相互作用理论来解释.通过Tauc-Lorentz色散模型拟合得到了303 K到453 K温度范围的Pb(Mg1/3Nb2/3)O3-0.3PbTiO3单晶光学常数及其随温度的变化规律, 发现折射率n随着温度的升高而升高.
Abstract
The optical properties of Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 single crystal near morphotropic phase boundary were investigated by temperature dependent transmittance and reflectance spectra. The temperature dependent absorption edges show blueshifts below 300 K while they show redshifts above 300 K. At 303 K, optical band gap Eg is 3.25 eV, critical point energies Ea and Eb are 3.93 and 4.65 eV, respectively. With increasing temperature, Eg, Ea and Eb decrease and they are 3.05, 3.57, 4.56 eV at 453 K, respectively. Three critical point energies Eg,Ea and Eb are corresponding to O 2p to Ti d, and Pb 6p, respectively. Such narrowing trends with increasing temperature can be explained by thermal expansion of the lattice and electron-phonon interaction. Based on Tauc-Lorentz dispersion models, the dielectric functions from 3.1 to 6.5 eV have been extracted from303 to 453 K. It was found that the refractive index n increases with increasing temperature.
诸佳俊, 张金中, 许桂生, 张小龙, 余温雷, 胡志高, 褚君浩. Pb(Mg1/3Nb2/3)O3-0.3PbTiO3单晶紫外可见近红外光学性质[J]. 红外与毫米波学报, 2015, 34(4): 442. ZHU Jia-Jun, ZHANG Jin-Zhong, XU Gui-Sheng, ZHANG Xiao-Long, YU Wen-Lei, HU Zhi-Gao, CHU Jun-Hao. UV-Vis-NIR optical properties of Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 single crystal[J]. Journal of Infrared and Millimeter Waves, 2015, 34(4): 442.