Thickness Dependent Characteristics of High Permittivity PMN-0.32PT Single Crystal for High Frequency Medical Imaging Applications

摘要

The dielectric, piezoelectric, and acoustic properties of PMN-0.32PT (Pb(Mg1/3Nb2/3) O3-PbTiO3) single crystals were investigated as a function of sample thickness ranging from 120 to 30 μm in order to enlighten the origin of property degradation of crystals for high frequency ultrasound applications. Electromechanical coupling factor(kt ), clamped and free dielectric constants decreased but sound velocity increased with decreasing crystal thickness. Particularly, repoling of the PMN-PT crystals would bring about a noteworthy enhancement in electromechanical and dielectric properties, which urges the importance of PMN-PT as a promising piezoelectric material for high frequency ultrasound transducers.