K改性的BNT-BZT压电陶瓷制备与性能研究

Preparation and Properties of K Doped(Bi,Na)TiO_3-Ba(Zr,Ti)O_3 Lead-Free Piezoelectric Ceramic

无铅压电陶瓷是压电材料中一个重要的研究方向,为了能够取代目前广泛应用的含铅材料,需要进一步提高无铅陶瓷材料的各项性能,尤其是压电性能。BNT-BZT系陶瓷是钛酸铋钠(BNT)和锆钛酸钡(BZT)两相形成的固溶体,在BNT-BZT陶瓷体系中,富BNT和低Zr含量的区域存在准同型相界,在相界附近可以得到性能优良的无铅压电陶瓷,其性能d33大约150pC/N,居里温度在240℃左右,介电常数大约900。在BNT-BZT相界点处掺杂K离子,研究了K改性的BNT-BZT体系陶瓷的微观结构与性能。实验结果表明,d33达到165pC/N;居里温度达到270℃;烧结中出现了玻璃相,预烧温度和烧结温度相对于原体系都有适当降低。

Microstructure, dielectric and piezoelectric properties of the morphotropic phase boundary composition in the system of K doped BNT-BZT have been investigated. The conventional processing method has been used to prepare the samples. A relatively high piezoelectric constant d33 of 165 pC/N and a Curie temperature of 270 ℃ have been obtained. In case of K addition, the sintering temperature decreases. Meanwhile these dielectric and piezoelectric properties make this composition a promising candidate as a lead-free piezoelectric ceramics