High performance PIN– PHT ceramics through addition of CuF2 and low-temperature sintering

Abstract

In this work, CuF2-doped 0.08 Pb(In0.5Nb0.5)O3–0.92 Pb(Hf0.47Ti0.53)O3 (PIN–PHT + CuF2) ceramics were prepared via traditional solid-state route using lower temperature than conventional environment. Resultant materials were found to have high Curie temperature, high mechanical quality factor and excellent piezoelectric performance. The phase composition as well as piezoelectric, dielectric and ferroelectric properties of the samples were detailedly studied, and Rayleigh's law fitting method was used to explore the piezoelectric response mechanism. Results indicate that the addition of CuF2 makes PIN–PHT lattice shrink, the phase composition of morphotropic phase boundary (MPB) is more symmetrical, that is, the content difference between rhombohedral and tetragonal phases decreases, and both intrinsic and extrinsic contributions of piezoelectric response are improved. For CuF2 doping content of 0.75-at%, samples sintering at 1100 °C exhibited excellent overall performance, its dielectric and piezoelectric properties at room temperature and Curie temperature reach excellent values, i.e., d33 = 488 pC/N, TC = 348 °C, εr = 1630, tan(δ) = 0.14%, Qm = 387, and kp = 0.6. More importantly, after depolarization at 200 °C, d33 still remained at 460 pC/N. The combined results show CuF2-doped PIN–PHT ceramics can be prepared at lower temperatures as well as have lower losses and higher values of Qm. These findings indicate that PIN–PHT + CuF2 ceramics have greater ease of production and significantly improved application prospects, particularly as a result of their high temperature stability.