弛豫铁电单晶的多功能特性及其器件应用

以Pb(Mg1/3 Nb2/3)O3-PbTiO3(PMN-PT或PMNT)为代表的弛豫铁电单晶具有远高于常用锆钛酸铅Pb(Zrx Ti1-x)O3(PZT)陶瓷的压电性能,引起了基于新一代压电单晶的功能器件研究热潮.本研究团队在国际上率先利用Bridgman方法生长出了大尺寸、高质量PMN-PT等弛豫铁电单晶(d33...

Multifunctional Properties and Device Applications of the Relaxor Ferroelectric Single Crystals

The relaxor ferroelectric single crystals, such as Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PMN-PT or PMNT), exhibit excellent piezoelectric performances, which are much higher than the conventional lead zirconate titanate Pb(Zr_xTi_1-x)O₃ (PZT) ceramics. The ultrahigh piezoelectric performances of the PMN-PT relaxor ferroelectric single crystals induce the research upsurge of the next generation of piezoelectric devices such as ultrasonic transducers. Our research team was the first time to use the Bridgman method to grow the large size and high quality PMN-PT relaxor ferroelectric single crystals (d₃₃~2 000 pC/N, k₃₃~92%) in the world. The growth, hierarchical structure and properties of the PMN-PT relaxor ferroelectric single crystals were systematically and deeply studied in our research team in the past 20 years. Different from the traditional perovskite ferroelectric materials, the PMN-PT relaxor ferroelectric single crystals have hierarchical microstructures, including monoclinic phase structure (M_A, M_B, M_C), domain configuration, nano-regions (PNRs), polarization rotation, resulting in the related research on the origin of ferroelectric materials with high piezoelectricity and the development of the fundamental theory on the ferroelectric physics. It was also found that the PMN-PT crystals exhibit outstanding pyroelectric properties, electro-optic (EO) properties and super high magnetoelectric coupling properties in the magnetoelectric composites composed with the magnetostrictive materials. Based on this, our team is also striving to promote the applications of relaxor ferroelectric single crystals on medical ultrasonic transducers, pyroelectric infrared (PIR) detectors, EO devices, magnetoelectric weak magnetic sensors and other devices. The research results of multifunctional properties and device application of the relaxor ferroelectric single crystals in our team about 20 years are summarized in this paper.