Ferroelectric and piezoelectric properties of 0.95(Na0.49K0.49Li0.02)(Nb0.8Ta0.2)O3–0.05CaZrO3 lead-free ceramics prepared by spark plasma sintering

Phase structure, dielectric, ferroelectric and piezoelectric properties of dense 0.95(Na0.49K0.49Li0.02)(Nb0.8Ta0.2)O3–0.05CaZrO3 lead-free ceramics prepared by spark plasma sintering (SPS) are reported. Compared with normal sintering, SPS yields a pseudocubic perovskite phase structure with a reduced c/a ratio, enhanced mechanical property and a lower Curie temperature. Large electric-field-induced strain of 0.135 % can be achieved at 4 kV/mm, accompanied with reduced ferroelectricity as evidenced by the slim polarization P(E) hysteresis loops and “sprout”-shaped bipolar strain curves. The piezoelectric strain is temperature insensitive in the range from room temperature to about 100 °C, featuring the current material promising potential for practical applications.