Sb掺杂对0.96(K_(0.49)Na_(0.51))(Nb_(0.97-x)Ta_(0.03)Sb_x)O_3-0.04Bi_(0.5)(Na_(0.8)K_(0.2))_(0.5)ZrO_3无铅压电陶瓷结构与电性能的影响研究

摘要

采用固相法制备了0.96(K_(0.49)Na_(0.51))(Nb_(0.97-x)Ta_(0.03)Sb_x)O_3-0.04Bi_(0.5)(Na_(0.8)K_(0.2))_(0.5)ZrO_3(0.96KNNTS_x-0.04BNKZ x=0,0.01,0.02,0.03,0.04)无铅压电陶瓷,研究了Sb掺杂量对0.96KNNTS_x-0.04BNKZ陶瓷相结构、微观结构和电性能的影响规律。X射线衍射(X-ray Diffraction,XRD)分析结果表明:0.96KNNTS_x-0.04BNKZ陶瓷具有纯钙钛矿结构,随着Sb掺杂量x的增加,陶瓷由正交-四方两相共存逐渐转变为四方相,在x≤0.01时,陶瓷为正交-四方两相共存的多型相转变(Polymorphic Phase Transition,PPT)结构,而当x≥0.02时,陶瓷则转变为四方相结构。在PPT向四方相转变的组成边界x=0.02处,陶瓷具有优异的电性能:压电常数d_(33)=345 pC/N,机电耦合系数k_p=39.2%,机械品质因数Q_m=51,介电常数ε_(33)~T/ε_0=1520,介电损耗tanδ=2.7%,剩余极化强度P_r=15.4μC/cm^2,矫顽场E_c=1.09 kV/mm,居里温度T_c=275℃。