电泳沉积PNN-PZT陶瓷厚膜及其电学性能研究

Electrophoretic Deposition and the Electrical Properties of the PNN-PZT Thick Films

利用电泳沉积法分别在Al2O3/Pt和Pt金属基底上制备了厚度为10～40μm的0.3Pb(Ni1/3Nb2/3)O3-0.7Pb(Zr,Ti)O3(PNN-PZT)厚膜,研究了pH值、Zeta电位与PNN-PZT悬浮液稳定性的关系,探索了沉积电压、沉积时间与电泳沉积量的关系.结果表明,当添加少量分散剂聚乙二醇时,pH值在3.5～5.5较宽的范围内,悬浮液具有较高的Zeta电位,容易制得稳定的悬浮液.沉积电压为21V,沉积时间为5min时,在Pt金属基底上电泳沉积得到的PNN-PZT厚膜,经过1200℃烧结30min后,SEM显微结构分析表明,厚膜致密,晶粒得到充分生长.电学性能测试显示此厚膜具有良好的铁电介电性能,其剩余极化强度P可达20.8μC/cm2,介电损耗tanδ为3.2%.

0.3Pb（Ni1/3Nb2/3）O3-0.7Pb（Zr,Ti）O3（PNN-PZT） thick films（10-40μm） were prepared by electrophoretic deposition method on Al2O3/Pt plates and Pt metallic foils.The effect of pH value on the stability of PNN-PZT suspensions was studied by measuring the zeta potential.The relationship among the deposition voltage,time and the quality of PNN-PZT films were investigated.When the pH value is in the range of 3.5-5.5,the suspension with the 2wt% PEG is stable.When the deposited voltage and time are 21V and 5min,respectively,the PNN-PZT thick films deposited on the Pt foil are uniform and free of crack.After sintering at 1200℃ for 30min,the PNN-PZT films with high density are obtained.The PNN-PZT thick films show the high ferroelectric and dielectric properties with the remnant polarization of 20.8μC/cm2 and the loss tangent of about 3.2% at 1 kHz.And the frequency dependences of the dielectric spectra of the PNN-PZT thick films show the relaxor property.The piezoelectric constant calculated from the S-V curve tested using the SPM is 67pm/V.