镨掺杂PZT95/5陶瓷的微结构转变与性能优化

Microstructure transition and properties optimization of PZT95/5 ceramic series doping with praseodymium

为探究镨掺杂对PZT95/5陶瓷微结构和性能的影响,以一氧化铅、氧化锆、二氧化钛和硝酸镨为原料,采用固相法制备镨离子掺杂PZT95/5陶瓷,分别利用X线衍射、扫描电子显微镜、精密阻抗分析仪和铁电分析仪对样品的微观结构、表面形貌、介电性能和铁电性能进行表征.结果表明:镨掺杂有利于PZT95/5陶瓷铁电三方相到反铁电四方相的微结构转变;掺杂镨可以使PZT95/5陶瓷样品的晶粒发育保持良好,晶粒分布更均匀,结构致密度也有所提高,但镨掺杂过量会抑制晶粒发育;随着镨掺杂量的增加,样品的相对介电常数呈现先增大后减小的趋势,在掺杂物质的量分数为3%时,相对介电常数最大,达到225.9,此时介电损耗为0.011 36;样品的剩余极化强度和矫顽场与介电常数呈现相同的变化趋势,镨掺杂物质的量分数为3%时,剩余极化强度最大,达到11.078 5μC/cm2,矫顽场最大为27.46 k V/cm.

To research the influence of doping with praseodymium to PZT95/5 ceramic, PZT95/5 ceramic doping with differ- ent content of praseodymium ions were prepared by the traditional solid-state reaction method using PbO, TiO2, ZrO2 and Pr （NO3）· 6H2O. The microstructure, surface morphology, dielectric properties and ferroelectric properties of the samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, precise impedance analyzer and ferroelec- tric tester. The results show that praseodymium doping benefits the transition from anti ferroelectric tetragonal phase to ferro- electric tetragonal phase; doping with some amount of praseodymium ions can keep the crystals to be well-developed, dis- tribute crystals more uniformly, and enhance the density of PZT95/5 ceramics, however, doping with excessive praseodymium ions would refrain crystals from growing up ; the relative dielectric constant of the PZT95/5 ceramic first increases and then decreases as the amount of praseodymium ions increase, the relative dielectric constant maximum is 225.93 when praseodymium doping mount is 3%, whose dielectric loss is 0.01136; the remanent polarization and coercive field of the sam- ples have the same changing trend, whose maximum are 11.0785 μC/cm2 and 27.46 kV/cm respectively when praseodymium doping mount is 3%.