Tailoring Electrical Properties and the Structure Evolution of (Ba0.85Ca0.15)(Ti0.90Zr0.10)1−x Li4x O3 Ceramics with Low Sintering Temperature

Abstract

The objective of this work is to lower the sintering temperature of (Ba0.85Ca0.15)(Ti0.90Zr0.10)O3 (BCZT) ceramics without sacrificing their piezoelectric performance. Li2CO3 was used as sintering aid so that BCZT ceramics with low sintering temperature were fabricated by conventional solid-state sintering. The sintering temperature of the BCZT ceramics was greatly decreased from 1450°C to 1260°C by introducing Li2CO3. The ceramics with a Li2CO3 content of x = 0.02 demonstrated outstanding piezoelectric and dielectric properties: d 33 = 436 pC/N, k p = 56%, Q m = 86, e r = 5185, tanδ = 0.017 and T c = 83°C. We explain the structural evolution in these ceramics through the growth mechanism of liquid-phase sintering, which includes 4 steps: (1) interface reaction in the initial state; (2) diffusion of Li2CO3 into BCZT grains; (3) densification by diffusion of CO2 through BCZT; and (4) improvement of properties by diffusion into the lattice of grain. As a result, Li2CO3 additive can effectively improve the piezoelectric properties of BCZT-based ceramics sintered at low temperatures.