Structure and electrical properties of MnO doped (Ba_(0.96)Ca_(0.04))(Ti_(0.92)Sn_(0.08)O_3 lead free ceramics

摘要

In this work, (Ba_(0.96)Ca_(0.04))(Ti_(0.92)Sn_(0.08))O_3-xmol MnO (BCTS-xMn) lead-free piezoelectric ceramics were fabricated by the conventional solid-state technique. The composition dependence (0 < x < 3.0 %) of the microstructure, phase structure, and electrical properties was systematically investigated. An O-T phase structure was obtained in all ceramics, and the sintering behavior of the BCTS ceramics was gradually improved by doping MnO content. In addition, the relationship between poling temperature and piezoelectric activity was discussed. The ceramics with x = 1.5 % sintering at temperature of 1330 °C demonstrated an optimum electrical behavior: d_(33) ~ 475 pC/N, k_p ~ 50 %, ε_r ~ 4060, tandδ~ 0.4 %, P_r ~ 10.3 μC/cm_2, E_c ~ 1.35 kV/mm, T_c ~ 82 °C, strain ~ 0.114 % and d~*_(33) ~ 525 pm/V. As a result, we achieved a preferable electric performance in BaTiO_3-based ceramics with lower sintering temperature, suggesting that the BCTS-xMn material system is a promising candidate for lead-free piezoelectric ceramics.