Effects of (Li, Ce, Y) co-substitution on the properties of CaBi2Nb2O9 high temperature piezoceramics

High temperature lead-free Bismuth layer-structured (Li, Ce, Y)-substituted CBN piezoelectric ceramics were prepared by the solid-state reaction method. The phase structure, microstructure, piezoelectric property, dielectric property, thermal stability and electric property of the (Li, Ce, Y)-substituted CBN ceramics were studied. X-ray diffraction and SEM revealed the doped ceramics had typical bismuth layer-structure. The piezoelectric coefficient was improved significantly and the maximum value was ~16.1 pC/N.The Curie temperature of all the samples were in the range of 925-941 °C that was close to or even excess the value of pure CBN ceramics. The resistivity were studied deeply and all the samples possessed excellent resistivity at high temperature (500 °C, ~106 Ω cm; 600 °C, ~105 Ω·cm). The thermal depoling behavior of the ceramics was researched in detail and the doped ceramics exhibited outstanding thermal stability. All the results indicate the (Li, Ce, Y)-substituted CBN ceramics possesses preeminent property, making it promising for application especially in high temperature territories.