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 ferroelectric structural materials (BLSFs), relative low piezoelectric coefficients (d33) and DC electrical resistivity (ρdc) impede high-temperature application of CaBi4Ti4O15 (CBT)s. In this work, Na+/Nd3+ co-doped Ca1-x(Na1/2Nd1/2)xBi4Ti4O15 (x = 0 - 0.12) ceramics were prepared by traditional solid-phase reaction method, and their microstructure and electrical properties were systematically investigated. The results show that with the increase of co-doping Na+/Nd3+ content, the grain size first increases and then slightly decreases. The piezoelectric properties and DC electrical resistivity (ρdc) of ceramic samples first increase and then slightly decrease. At x = 0.09, Ca0.91(Na1/2Nd1/2)0.09Bi4Ti4O15 has both high piezoelectric coefficient (d33 = 24 pC/N) and high temperature DC electrical resistivity (ρdc=5.6 × 106 Ω·cm@600 ℃), as well as the 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.