中文摘要：

以硝酸锆（Zr（NO3）4·5H2O）,乙酸铅（Pb（CH3COO）2·3H2O）,钛酸四丁酯（Ti（OC4H9）4）和聚乙烯吡咯烷酮（PVP）为原料,采用sol-gel和静电纺丝法,结合烧结工艺首次制备了在准同型相界附近的类单晶PZT纳米纤维.利用热重分析、X射线衍射仪、扫描电镜和透射电镜等表征方法,对类单晶PZT纤维的热分解过程、晶体结构、微观相貌和形成机理等进行了分析和解释.研究结果表明：经过400℃预退火0.5h以及750℃烧结2h后,可形成具有类单晶结构的PZT纳米纤维,纤维直径约在80 ～ 100 nm左右,晶体结构为典型的钙钛矿相.形成这种类单晶结构的主要机理是在预退火期,有机物充分分解形成无规则非晶网络,随着烧结温度的升高,取向基本一致的小晶粒经历了形核、长大、吞噬,最终形成类单晶纳米纤维.在准同型相界附近的类单晶PZT纳米纤维在纳米压电器件和微机电系统领域具有广泛的应用前景.

英文摘要：

Single-crystal-like lead zirconate titanate （PbZr0.52Ti0.48O3,PZT） ceramic fibers were successfully prepared by sol-gel based electrospinning and subsequent calcination process.The thermo-decomposition process,fiber morphology,crystal structure and formation mechanism of the single-crystal-like PZT nanofibers were characterized using the thermogravimetry/differential scanning caborimetry （TG/DSC）,X-ray diffraction （XRD） and transmission electron microscopy （TEM）.The fiber was smooth and uniform with a diameter of ～ 80 to ～ 100 nm.The crystal structure of the nanofibers pyrolyzed at 400 ℃ for 0.5 h and calcined at 750 ℃ for 2 h was proved to be single-crystal-like tetragonal perovskite phase.The formation mechanism was proposed as follows：For the pyrolysis process,the polymer was decomposed completely; When the calcination temperature increased,the new-formed nanocrystallites oriented growed at the nuclei sites and aggregated into large single crystals of preferred orientation that retain the morphology of the original shape.Such single-crystal-like PZT nanofibers with a near MPB composition have therefore been a milestone for piezoelectric nanodevices with significantly enhanced performance.