For antiferroelectric (AFE) energy storage, the stability of energy storage density and conversion efficiency against wide temperature (T) range and broad frequency (f) band is highly preferred. In this work, we investigate the energy storage and associated kinetics of polarization switching in (001)-textured AFE Pb0.97La0.02(Zr0.95Ti0.05)O3 (PLZT 2/95/5) thick films prepared by sol-gel method. A recoverable energy storage density (Wre) of ∼26.8 J/cm3 and an energy conversion efficiency (η) as high as ∼62.5% have been obtained under an electric field of 1.85 MV/cm and room temperature. Both the Wre and η are only weakly T-dependent up to 280 °C and weakly f-dependent ranging from 20 Hz to 10 kHz. The high frequency stability originates from the rapid polarization switching as identified by the nucleation-limited-switching theory, suggesting a characteristic switching time as short as ∼3 ns, favorable for applications in pulse energy storage.

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Rui-Peng(杨瑞鹏) a) , Lin Si-Xian(林思贤) a) , Fang Xiao-Gong(方潇功) a) , Qin Ming-Hui(秦明辉) a) , Gao Xing-Sen(高兴森) a) , Zeng Min(曾 敏) a) † , and Liu Jun-Ming(刘俊明) b) a)

The magnetic properties of Mg-doped BiFeO3 (BFO) with and without oxygen vacancies are studied through first-principles calculations. The Mg-doping prefers to occupy the ferromagnetic planes and produces an obvious improved magnetization, and the magnetization is linearly enhanced with increasing Mg-doped content, which is consistent with the trend reported in experiment. However, our calculated result is significantly larger than the experimental one, and the reason is revealed that the relative energy differences of various spin-ordering configurations are small. Furthermore, oxygen vacancy in Mg-doped BFO can further enhance the magnetization, while keeping the insulating band gap character. The calculated results imply that the oxygen vacancy in Mg-doped BFO would be an effective way to improve the multiferroicity of BFO.

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