0.06BiYbO_(3)-0.94Pb(Zr_(0.48)Ti_(0.52))O_(3)三元系压电陶瓷的氧化物掺杂改性研究

Doping Effects of Oxides on 0.06BiYbO_(3)-0.94Pb(Zr_(0.48)Ti_(0.52))O_(3)Ternary Piezoceramics

针对新一代声波测井仪器对其核心元件压电陶瓷兼具高居里温度、高压电系数以及高稳定性要求的迫切需求,本文采用传统的固相反应-无压烧结技术制备了一种0.06BiYbO_(3)-0.94Pb(Zr_(0.48)Ti_(0.52))O_(3)(BY-PZT)三元系压电陶瓷,并研究了四种氧化物掺杂对其微观结构及电学性能的影响。由XRD和SEM表征可知所有样品均呈纯四方相钙钛矿结构,掺杂Cr_(2)O_(3)的样品平均晶粒尺寸最大。介电温谱和谐振频谱研究证实四种氧化物掺杂均能提高其介电性能的温度稳定性。掺杂La_(2)O_(3)的样品介电常数温度系数(Tk_(ε))最低,掺杂MnO_(2)的样品机械品质因素(Q_(m))最高,而掺杂CeO_(2)的样品抗热退极化性能最好。高温复阻抗(Cole-Cole图)分析表明,Cr_(2)O_(3)掺杂能够显著提高BY-PZT陶瓷的高温电阻率,陶瓷在高温下的电导行为主要由晶界响应控制。综合来看,掺杂La_(2)O_(3)的样品兼具高居里温度(T_(C)=397℃)和高压电系数(d_(33)=290 pC/N),并且在300℃退火4 h后d_(33)仍能保持在270 pC/N左右,有望在极限工作温度为300℃的高温压电器件中获得应用。

Aiming at the urgent demand of the new generation of sonic logging tools for their core components,piezoelectric ceramics,which have high Curie temperature,high voltage electrical coefficient and high stability,0.06BiYbO_(3)-0.94Pb(Zr_(0.48)Ti_(0.52))O_(3)(BY-PZT) ternary piezoceramics with addition of different oxide additives were prepared by traditional solid-state reaction method.The effects of oxide additives on the phase structures and electrical properties of the BY-PZT ternary piezoceramics were investigated.XRD and SEM analysis show that all samples are pure tetragonal perovskite structure.When doped with Cr_(2)O_(3),the average grain size of the samples has a maximum value.Dielectric temperature spectrum and resonance spectrum analysis illustrated that doping of four kinds of oxide improved the temperature stability of dielectric properties respectively.The lanthanum-doped sample got the lowest temperature coefficient of dielectric constant(Tk_(ε)).The mechanical quality factor(Q_(m)) has a maximum value when MnO_(2)are doped;but the samples doped with CeO_(2)have the best thermal depolarization resistance.The analysis of high temperature complex impedance(Cole-Cole) shows that Cr_(2)O_(3)doping significantly improve the high temperature resistivity of the ceramic.It is found that the electrical conduction behavior of the ceramics at high temperature is dominated by the grain-boundary response.The lanthanum-doped sample has both high Curie temperature(T_(C)=397 ℃) and high piezoelectric constant(d_(33)=290 pC/N),and after annealed at 300 ℃ for 4 h,the d_(33) value of the sample still retains above 270 pC/N,which provides great promising for application in the high-temperature piezoelectric devices with an extreme operating temperature of 300 ℃.