KNNS-BNKZ无铅压电陶瓷的制备及其电性能研究

Study on Preparation and Electrical Properties of KNNS-BNKZ Lead-Free Piezoelectric Ceramics

采用传统固相法中的直接合成法和两步合成法制备了0.96(K_0.48Na_0.52)(Nb_1-x_Sb_x)O_3-0.04(Na_0.82K_0.18)_0.5Bi_0.5ZrO_3(KNNS-BNKZ)无铅压电陶瓷,研究了(Bi,Na,K)ZrO_3添加方式,以及Sb摩尔分数对KNNSBNKZ材料显微组织结构和电性能的影响规律。结果表明,采用直接合成法得到的KNNS-BNKZ陶瓷在室温下为四方相,而采用两步合成法得到的陶瓷在室温下为正交-四方两相共存,且随着Sb摩尔分数的增加,陶瓷材料的密度增大,室温下的相对介电常数增大,压电常数增大,居里温度降低。采用两步合成法制备的Sb摩尔分数为0.06的KNNS-BNKZ陶瓷具有最佳电性能:室温下,相对介电常数εr=1 659,介电损耗tanδ=0.038,居里温度T_C=243℃,压电常数d_33=138pC/N。

The 0.96（K0.48Na0.52）（Nb1-xSbx）O3-0.04（Na0.82K0.18）0.5Bi0.5ZrO3（KNNS-BNKZ）lead-free piezoelectric ceramics were prepared by the direct synthesis and two-step synthesis method.The effects of different addition ways of the（Bi,Na,K）ZrO3（BNKZ）and the amount of Sb on the microstructure and electrical properties of KNNS-BNKZ ceramics were studied.The results showed that the phase structure of KNNS-BNKZ ceramics prepared by direct synthesis method were tetragonal phase at room temperature,while the ceramics prepared by twostep synthesis were orthorhombic-tetragonal co-existence.The density,the dielectric constantεr,the piezoelectric coefficient d33 of samples prepared by two-step synthesis method increased with the increase of Sb content,while the Curie temperature（TC）decreased.And the optimized electrical properties can be obtainedwhen the Sb content was0.06,withεrof 1 659,tanδof 0.038,TCof 243 ℃,and d33 of 138 pC/N.