Device-relevant properties of [010]-oriented undoped TGS single crystals grown above and below the phase transition temperature

摘要

Undoped triglycine sulfate (TGS) crystals grown above and below its Curie temperature (T_c) along [010] polar direction by unidirectional solution growth method were characterized to measure and compare their device-relevant properties. The powder XRD was used for phase confirmation. The piezoelectric coefficient of TGS crystal grown below T_c was higher than that grown above T_c, and the P-E hysteresis studies show well-saturated hysteresis loops for both the crystals and the values of remnant polarization and coercive field were higher for crystal grown above T_c as compared to crystal grown below T_c. These observations were explained on the basis of the concentration of point defects and their influence on the domain nucleation and mobility. The crystal grown above T_c also exhibits higher dielectric permittivity, high mechanical hardness, low dislocations defects density, showing its improved device potential com-pared to TGS crystal grown below T_c. The probable reasons for the characteri-zation results have been presented.