Structural and electrical properties of (1−x)Bi(Ga1/4Sc3/4)O3–xPbTiO3 piezoelectric ceramics

Abstract

Bismuth containing crystalline solutions $\text{(1−x)}{\mathrm{Bi(Ga}}_{\mathrm{1/4}}{\mathrm{Sc}}_{\mathrm{3/4}}{\mathrm{)O}}_{\mathrm{3}}\mathrm{–x}{\mathrm{PbTiO}}_{\mathrm{3}}$ (BGS–PT) have been developed using conventional ceramic technology. X-ray diffraction analysis reveals that BGS-PT has a perovskite structure, in which tetragonal to rhombohedral phase transformation appears for $\text{x=0.6.}$ The dielectric properties were investigated at room and elevated temperatures, respectively, for different PT contents. BGS–PT for $\text{x=0.6}$ shows enhancement in dielectric constant K and piezoelectric constant $d_{33}$ of 1180 and 124 pC/N, respectively, for the compositions investigated. The Curie temperature ${\mathrm{(T}}_c)$ of BGS–PT is in the range of $\text{465–510\hspace{0.05em}°}\mathrm{C}$ at least $\text{100\hspace{0.05em}°}\mathrm{C}$ higher than that of conventional ${\mathrm{Pb(Zr,Ti)O}}_{\mathrm{3}}$ piezoelectric ceramics. The coercive field ${\mathrm{(E}}_c)$ of BGS–PT strongly depends on the PT content and can reach 75 kV/cm for $\text{x=0.8.}$ Our results show that BGS–PT is a good low-lead high-temperature piezoelectric ceramic.