Preparation, Properties And Application Of PMN-PT-based Transparent Electro-optical/piezoelectric Ceramics

Ferroelectric materials with high piezoelectricity and high transparency have excellent electro-optic,acousto-optic,and acousto-optic-electric coupling effects,which is a new research hotspot in some technical fields such as electro-optic modulators,optical phased arrays,quantum optical devices,and photoacoustic imaging systems.The new ferroelectric functional materials,(1-x)Pb(Mg_1/3Nb_2/3)O₃-x Pb Ti O₃(abbreviated as PMN-PT),have the highest piezoelectric properties,but the ferroelectric domain structure and complex microstructure have seriously affected its transparency.In this paper,the preparation process of Sm³⁺doped PMN-PT transparent ceramics was studied based on the preparation experience of PMN-PT transparent ceramics.The electro-optic and piezoelectric properties of PMN-PT transparent ceramics were studied by changing the solid solution ratio and rare earth doping,what's more,the application of electro-optic and piezoelectric properties was preliminarily explored.The main work and results are as follows:1.0.88PMN-0.12PT transparent electro-optic ceramics and 0.70PMN-0.30PT transparent piezoelectric ceramics with different Sm³⁺doping were prepared by the two-step sintering method.XRD results show that PMN-PT transparent ceramics are pure perovskite structures.SEM results show that the transparent ceramics are highly dense.The ferroelectric,piezoelectric,dielectric,strain,transmittance,luminescence,and electro-optic properties of PMN-PT transparent ceramics were measured and analyzed.It is found that with the increase of Sm³⁺doping,the grain size of ceramics increases,the relaxation of ceramics increases,the ferroelectricity decreases,the electro-optic coefficient decreases,the half-wave voltage increases,the extinction ratio increases,and the piezoelectric properties increase first and then decrease.2.The 0.88 PMN-0.12 PT transparent electro-optic ceramics with 0.5%mol Sm³⁺doping has the best comprehensive performance,which transparency reached 69.6%(the theoretical limit is 71%),quadratic E-O coefficient reached 35×10^-16 m²/V²,extinction ratio was 32 d B and half-wave voltage was only 113 V when d=L=1 mm.Those performances are better than that of commonly used electro-optic materials such as Li Nb O₃,KDP,and PLZT.The 0.70PMN-0.30 PT transparent piezoelectric ceramics with 2.5%mol Sm³⁺doping has the best electromechanical conversion performance,which piezoelectric coefficient d₃₃ reached 1403p C/N,and the electromechanical coupling coefficient k_p was closed to 80%.3.Using our PMN-PT transparent ceramic and laser,signal generator,high voltage generator,signal receiver,STM32 microcomputer,etc.we designed an electro-optic modulation system,which realizes the real-time transmission of digital signal and analog signal,verifies the feasibility of the application of PMN-PT transparent ceramics in optical communication.And we used 0.70 PMN-0.30 PT transparent piezoelectric ceramics to study the application of piezoelectric PMN-PT ceramics in piezoelectric energy harvesting.