JIANG Fulan, WANG Pengbin, JIANG Xiangping
(Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China)
Abstract: Up-conversion (UC) and electrical properties of Na0.5Bi8.5-xHoxTi7O27 (NBT-BIT-xHo3+, 0 ≤ x ≤ 0.02) bismuth layered lead-free piezoelectric ceramics were studied. Results show that all the NBT-BIT-xHo3+ samples possessed a single-phase inter-growth structure. With Ho3+ concentration increasing, the Curie temperature Tc increased from 650 °C to 668 °C. The electrical properties of the samples can be optimized by the addition of Ho3+ content, and the sample with x = 0.01 has the optimum electrical properties: d33= 21pC/N, Qm = 2887, tanδ = 0.78%. Under the 980 nm near infrared excitation, NBT-BIT-xHo3+ samples give off green and red emissions corresponding to the 5S2/5F4→5I8 (550 nm) and 5F5→5I8 (657 nm) transitions, respectively. The emission colors of NBT-BIT-xHo3+ ceramic samples are adjustable from yellowgreen to green by changing Ho3+ concentration. The NBT-BIT-xHo3+ ceramics have potential applications for high temperature piezoelectric and electro-optical integration devices.
Key words: bismuth layer-structured; piezoelectric ceramics; photoluminescence; dielectric properties