（Na0.5Bi0.5）0.945Ba0.055TiO3单晶的生长及光学性能研究

摘要

(Na0.5Bi0.5)0.945Ba0.055TiO3(abbreviated as NBBT5.5) crystal with dimensions of Φ35 mm×12 mm was grown by the top-seeded-solution growth method with self flux though the cooling oxygen;The structure,thermal,optical and piezoelectric properties were investigated.XRD of crushed powder of NBBT indicated that the crystal is perovskite-type structure.The temperature of calcined and sintering was measured by the DSC-TG patterns that can improve the technology of NBBT crystals growth,so it can decrease the evaporation of Bi2O3 and Na2O.The excellent optical appearance of the NBBT5.5 crystal shows the transmittance decreases to zero at the wavelength of approximately 369 nm.For wavelengths longer than 390 nm,the films are transparent.The optical transmittance of the NBBT5.5 crystal was high enough(72% transmittance at wavelength above 1 000 nm) to be a candidate for many electro-optical applications.The piezoelectric constant d33 values of 438 pC/N are obtained,showing that they could be promising candidates as lead-free piezoelectric materials.%采用顶部风冷籽晶助熔剂法成功生长出了（Na0.5Bi0.5）0.945Ba0.055TiO3（简称NBBT5.5）晶体,晶体尺寸达到了Φ35mm×12mm;研究了粉料的热学性质、晶体的结构、光学性能及压电性能.实验结果表明,晶体具有三方相四方相共存的钙钛矿结构.通过研究粉料的DSC-TG曲线,得到了制备单晶材料的预烧结的温度以及烧结温度,优化了NBBT单晶材料的制备工艺,降低了Bi2O3和Na2O的挥发.晶体具有优良的光学性能,在369nm处晶体处于全吸收,390nm以上晶体是透明的,1 000nm处透过率达到72%.NBBT5.5晶体的压电常数d33为438pC/N,是一种极具应用潜力的无铅压电材料.