Energy storage density of tailored relaxor-antiferroelectric state in Gd-doped Ag(Nb0.8Ta0.2)O3 ceramics

Antiferroelectric state AgNb0.8Ta0.2O3 ceramics can be adjusted by doping with Gd to form the relaxor-antiferroelectric state (Ag1-3xGdx)(Nb0.8Ta0.2)O3 ceramics (x = 0, 0.01, 0.02, 0.03, 0.04) for energy storage applications. The superb recoverable energy density (Wrec) of ∼9.47 J cm−3 at x = 0.01 and energy storage efficiency (η) of ∼68 % at x = 0.02 can be achieved at 375 kV cm−1. The superb Wrec can be attributed to phase evolution modulated with optimal fractions of ferroelectric Pmc21, antiferroelectric Pnma, and nonpolar cubic Pm-3m symmetries. Polarization-electric field (P-E) hysteresis loop, dielectric permittivity, atomic vibration, and electron diffraction pattern were used to probe the mechanism of superb recoverable energy density.