Enhanced piezoelectric properties and electrical resistivity of Na+/Nd3+ co-doped Ca1−x(Na1/2Nd1/2)xBi4Ti4O15 ceramics for high-temperature applications†
Abstract
In bismuth layered structure ferroelectrics (BLSFs), relatively low piezoelectric coefficients (d33) and DC electrical resistivity (ρdc) impede the high-temperature application of CaBi4Ti4O15 (CBT). In this work, Na+/Nd3+ co-doped Ca1−x(Na1/2Nd1/2)xBi4Ti4O15 (x = 0–0.12) ceramics were prepared using traditional solid-phase reaction method, and their microstructure and electrical properties were systematically investigated. The results show that with increasing Na+/Nd3+ co-doping content, the grain size first increases and then slightly decreases. The piezoelectric properties and DC electrical resistivity (ρdc) of the ceramic samples first increase and then slightly decrease. At x = 0.09, Ca0.91(Na1/2Nd1/2)0.09Bi4Ti4O15 exhibits a high piezoelectric coefficient (d33 = 24 pC N−1) and high temperature DC electrical resistivity (ρdc = 5.6 × 106 Ω cm at 600 °C), as well as a high Curie temperature of 761 °C. The enhancement in overall performance suggests that Na+/Nd3+ co-doped CBT ceramics are promising candidate materials for high-temperature piezoelectric applications.