Electrical And Optical Properties Of Rare Earth Ion-doped PMT-PT Crystals

Pb(Mg1/3Ta2/3)O3-PbTiO3(PMT-PT)relaxor ferroelectric crystals have attracted extensive research due to their excellent electrical properties in recent years.Based on the unique electromechanical conversion effect,PMT-PT crystal becomes a potential material for brake,transducer,sensor and other electronic devices.However,the Curie temperature(TC?48?)and coercive field are low(EC?5.3 kV/cm),so it is not suitable for use in high temperature and high power environment.The weak optical properties also limit its application in optical devices.In this paper,rare earth ions Er3+ and Yb3+ were introduced into PMT-PT crystal to improve the electrical properties and optical properties of the crystal.The phase structure,macroscopic and microscopic structure and photoluminescence properties of the crystal were studied.PMT-38PT,PMT-38PT:Er,PMT-49PT and PMT-49PT:Er/Yb were grown by high temperature solution method.Through X-ray diffraction test,the phase structure of the grown crystals is pure perovskite structure,and the rare earth ions Er3+and Yb3+are diffused into the crystal lattice of PMT-PT,so that the crystal has optical properties.Scanning electron microscopy shows the layered growth pattern of the crystal.It is found that the piezoelectric constant of PMT-38PT is 220-260 pC/N,the dielectric constant is 12254,and the Curie temperature of the crystal is 52?.The electric hysteresis loop of PMT-38PT is tested at-70?,and the coercive field EC and the residual polarization Pr are 9.8 kV/cm and 25 ?C/cm2,respectively.When rare earth ion Er3+ is added into PMT-38PT,it is found that the the Curie temperature of the crystal is 48?,and the dielectrical constant is 10975.However,the piezoelectric constant and coercive field are increased d33=300-420 pC/N? Ec=14.34 kV/cm.The crystal emits green and red light under the laser excitation at 980 nm,and the corresponding energy levels of 2H11/2,4S3/2 and 4F9/2 transition to the ground state energy levels of 4I15/2.The average life of PMT-38PT:Er crystal is 45.89 ?s.The permittivity of PMT-49PT and PMT-49PT:Er/Yb crystals at room temperature are 5196.9 and 4327.31,respectively,with the increase of PT content.However,the piezoelectric constant and Curie temperature increased significantly.The maximum piezoelectric constant was d33?823 pC/N,and the Curie temperature Tc was 101.2? and 107.5?,respectively.Under the action of electric field of 30 kV/cm and temperature of-50?,the intensity of coercive field of PMT-49PT:Er/Yb crystal is 8.48 kV/cm,and the residual polarization intensity is 20.88?C/cm2.Under 25 kV/cm polarized electric field at room temperature,the intensity of coercive field is 6.19 kV/cm,and the residual polarization intensity is 18.32 ?C/cm2.Under the excitation of 980 nm laser,PMT-49PT:Er/Yb crystal has the strongest emission peak at 563 nm,showing strong photoluminescence properties.The average luminous lifetime of PMT-49PT:Er/Yb crystal is 60.47 ?s excellent low temperature performance of PMT-PT opens up a possibility for the application of materials in low temperature environment.The doping of rare earth ions makes the crystal have optical properties,which provides the possibility for the application of optical devices and the study of photoelectric coupling.