High piezoelectric properties and good temperature stabilities of CuO-modified Ba(Ti0.96SnxZr0.04-x)O3 ceramics

In order to obtain both high piezoelectric property and good temperature stability in BaTiO 3-based ceramics in the common usage temperature range, Sn 4+ and Zr 4+ are co-doped into BaTiO 3 ceramics according to the formula of Ba ( Ti 0.96 Sn x Zr 0.04-x) O 3 (BTSZ) (x = 0.01–0.4) with 1 mol% CuO being added as sintering-aid in this study. The CuO -modified BTSZ ceramics show both high piezoelectric properties and good temperature stability. Particularly, the CuO -modified Ba ( Ti 0.96 Sn 0.01 Zr 0.03) O 3 ceramic displays the high piezoelectric properties of d33 = 350 pC/N, k p = 49.5% at room-temperature and a weak temperature dependence of kp in the temperature range of -15°C and 60°C. Moreover, the CuO -modified Ba ( Ti 0.96 Sn 0.01 Zr 0.03) O 3 ceramic shows stable thermal aging behavior with the d33 being almost unchanged until the aging temperature of 100°C, which is even higher than its Curie temperature. The high piezoelectric properties of CuO -modified Ba ( Ti 0.96 Sn 0.01 Zr 0.03) O 3 ceramic were ascribed to the dense microstructure with small and uniform grain size distribution. The stable thermal aging behavior can be explained by the aging effect based on the defect dipolar model.

High Piezoelectric Property and Low Dielectric Constant PZN-PZT Ceramics

The influences of the substitution of (Zn1/3Nb2/3) group for Ti as well as addition of Fe2O3 and K2CO3 on d33, kp, εr, and tgδ of the Pb[Zr0.46Ti0.54-x(Zn1/3Nb2/3)x]O3 + y mol%Fe2O3+z mol%K2CO3 (PZNPZT) (0 ≤ x ≤ 0.20, 0 ≤ y ≤ 0.10, 0 ≤ z ≤ 0.20) ceramics were investigated. The experimental results demonstrated that when x increases in Pb[Zr0.46Ti0.54-x(Zn1/3Nb2/3)x]O3+0.3 mol%Fe2O3+0.5mol%K2CO3 ceramics, the d33, kp, εr, and tgδ increase and approach to their maximum values, then eventually decrease. XRD analysis revealed that the perovskite structure of the materials transfers from tetragonal phase to rhombohedral phase. The relative dielectric constant (εr) decreases dramatically in the rhombohedral phase area near the MPB; the d33 and εr decrease with the small amount of added Fe2O3 and K2CO3, which also contributes to densification of the PZN-PZT ceramics. The optimized piezoelectric performances through the experiment were obtained as d33=280 pC/N, kp=0.62, εr=900, tgδ=0.003.