Effect of Co2+ substitution in B-sites of the perovskite system on the phase formation, microstructure, electrical and magnetic properties ofBi0.5(Na0.68K0.22Li0.10)0.5TiO3 ceramics

• Published in: 矿物冶金与材料学报 2022, Vol.29 (9), p.1798-1808
• Main Authors: Pamornnarumol Bhupaijit, Chonnarong Kaewsai, Tawat Suriwong, Supree Pinitsoontorn, Surirat Yotthuan, Naratip Vittayakorn, Theerachai Bongkarn
• Format: Article
• Language: English
• ISSN: 1674-4799

Bi0.5(Na0.68K0.22Li0.10)0.5Ti1–xCoxO3 lead-free perovskite ceramics (BNKLT–xCo, x = 0, 0.005, 0.010, 0.015 and 0.020) were fabric-ated via the solid-state combustion technique. A small-amount of Co2+ ion substitution into Ti-sites led to modification of the phase formation, microstructure, electrical and magnetic properties of BNKLT ceramics. Coexisting rhombohedral and tetragonal phases were observed in all samples using the X-ray diffraction (XRD) technique. The Rietveld refinement revealed that the rhombohedral phase increased from 39％ to 88％ when x increased from 0 to 0.020. The average grain size increased when x increased. With increasing x, more oxygen vacancies were generated, leading to asymmetry in the bipolar strain (S–E) hysteresis loops. For the composition of x = 0.010, a high dielectric constant (εm) of 5384 and a large strain (Smax) of 0.23％ with the normalized strain(d?33)of 460 pm·V–1 were achieved. The BNKLT–0Co ceramic showed dia-magnetic behavior but all of the BNKLT–xCo ceramics exhibited paramagnetic behavior, measured at 50 K.