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采用固相法制备Na_(0.25)K_(0.25)Bi_(2.5–x)Nd_xNb_2O_9(NKBN–xNd~(3+),0≤x≤0.40,x为摩尔分数)铋层状无铅压电陶瓷,研究了不同Nd~(3+)掺杂量对NKBN–x Nd陶瓷显微结构、电学性能的影响及NKBN–0.20Nd~(3+)陶瓷高温下的电导行为。结果表明:所有样品均为单一的铋层状结构;当Nd~(3+)的掺杂量x为0.02时,样品的晶粒尺寸减小并趋于均匀,致密度提高;适量的Nd~(3+)掺杂能降低样品的介电损耗,提高NKBN陶瓷的压电常数d33。NKBN–0.20Nd~(3+)陶瓷样品的电学性能最佳:压电常数d_(33)=24 p C/N,机械品质因数Q_m=2 449,tanδ=0.40%,2P_r=1.11μC/cm~2。NKBN–0.20Nd~(3+)样品的阻抗谱表明:在高温区域陶瓷的晶粒对电传导起主要作用,当温度高于600℃时,样品主要表现为本征电导,NKBN–0.20Nd~(3+)和NKBN的电导活化能分别为1.85和1.64 e V。
The bismuth layered lead-free piezoelectric ceramics were prepared by the solid-state method. The bismuth layered lead-free piezoelectric ceramics were prepared by solid state reaction, The effects of Nd 3+ doping amount on the microstructure and electrical properties of NKBN-x Nd ceramics and the conductance behavior of NKBN-0.20Nd 3+ ceramics at high temperature were investigated. The results show that all the samples are single bismuth layered structure. When the doping amount of Nd 3+ is 0.02, the grain size decreases and tends to be uniform and the density increases. (3+) doping can reduce the dielectric loss of the sample and increase the piezoelectric constant d33 of NKBN ceramics. The electrical properties of NKBN-0.20Nd ~ (3+) ceramics were the best: piezoelectric constant d_ (33) = 24 p C / N, mechanical quality factor Q_m = 2 449, tanδ = 0.40%, 2P_r = 1.11μC / cm ~ 2. The impedance spectra of NKBN-0.20Nd ~ (3+) samples show that the grains of ceramic have a major effect on the electrical conduction at high temperature. When the temperature is higher than 600 ℃, the samples mainly exhibit intrinsic conductance, NKBN-0.20Nd ~ The conductance activation energies of (3+) and NKBN are 1.85 and 1.64 eV, respectively.