Existence of [B3-O6]3- hexagonal ring growth unit in melt solution of β-BaB2O4 crystal was proved by the results of high temperature Raman measurements.A morphology evolution process of β-BaB2O4 crys-tal was observed by a high temperature in-situ observation device.The crystal morphology varied with the supersaturation of growth melt solution.The mechanism of β-BaB2O4 crystal morphology evolution was analyzed through the growth unit model.
HE ChongJun1,ZHONG WeiZhuo2 & LIU YouWen1 1 College of Science,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China
采用助溶剂法生长了掺杂量分别为0.1wt%和0.01wt%的0.67PMNT-0.33PT单晶.利用二波耦合实验研究了掺铁的弛豫铁电单晶0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3(PMN-PT)的光折变性能.本文测了样品的消光光谱、电光系数、光诱吸电场和光电.最大的增益系数达了21 cm 1,是无掺杂的PMN-PT晶体的两倍.光栅形成速率随铁浓度的升高而降低.
0.91Pb(Zn1/3Nb2/3)O3-0.09PbTiO 3(PZN-9%PT) single crystals with different orientations are investigated by using a spectroscopic ellipsometer,and the refractive indices and the extinction coefficients are obtained.The Sellmeier dispersion equations for the refractive indices are obtained by the least square fitting,which can be used to calculate the refractive indices in a low absorption wavelength range.Average Sellmeier oscillator parameters E o,λ o,S o,and E d are calculated by fitting with the single-term oscillator equation,which are related directly to the electronic energy band structure.The optical energy bandgaps are obtained from the absorption coefficient spectra.Our results show that the optical properties of [001] and [111] poled crystals are very similar,but quite different from those of the [011] poled crystal.
