Wide temperature stability of (Sr, Ca, Bi)TiO3-Bi(Mg0.5Zr0.5)O3 ergodic relaxor ferroelectrics with a diffuse phase transition.

In this study, (1− x)Sr 0.49 Ca 0.21 Bi 0.2 TiO 3 - x Bi(Mg 0.5 Zr 0.5)O 3 ergodic relaxor ferroelectric ceramics were synthesized via a solid-state reaction method. The addition of Bi(Mg 0.5 Zr 0.5)O 3 expanded the temperature range for thermal activation of polar nanoregions (PNR s), resulting in high ergodicity of PNR s from 0 °C to 100 °C, leading to a broad dielectric constant plateau. Thus, the 0.95SCBT-0.05BMZ ceramic satisfied X9R requirements for capacitance temperature stability with a low temperature coefficient of 160 ppm/°C. The wide thermal activation temperature range also contributed to an increase in quantity rather than size of PNR s under applied electric field, thereby exhibiting diffuse phase transition (DPT) with high polarization response speed in SCBT-BMZ ceramics. Notably, the energy storage density of 2.81 J cm−3 was achieved by the 0.975SCBT-0.025BMZ relaxor ferroelectric ceramic under an electric field of 340 kV cm−1, demonstrating an efficiency of 89 %, a discharge energy density variation rate (from 0 °C to 100 °C) at only 9.7 %, and a transitory discharge time (t 0.9 ≈ 90 ns). • Lattice distortion expands the temperature range for thermal activation of PNR s. • DPT is attribute to the easy generation of PNR s under electric field. • High ergodic PNR s contributes to fast polarization response and transitory discharge time. [ABSTRACT FROM AUTHOR]