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Antiferroelectric (Pb0.87Sr0.05Ba0.05La0.02)(Zr0.52Sn0.40Ti0.08)O3 thin film capacitors were fabricated for dielectric energy storage. Thin films with excellent crystal quality (FWHM 0.021°) were prepared on (100) SrRuO3/SrTiO3 substrates by pulsed laser deposition. The out-of-plane lattice constant of the thin film was 4.110 ± 0.001 Å. An average maximum recoverable energy storage density, 88 ± 17 J cm−3 with an efficiency of 85% ± 6% at 1 kHz and 80 ± 15 J cm−3 with an efficiency of 91% ± 4% at 10 kHz, was achieved at room temperature. The capacitor was fatigue resistant up to 106 cycles at an applied electric field of 2 MV cm−1. These properties are linked to a low level of hysteresis and slow polarization saturation. PbZrO3-derived oxide thin film capacitors are promising for high efficiency and low loss dielectric energy storage applications. 

In this work with a model system (Ba,Ca)TiO3, we analyze the morphologies of CaTiO3-rich precipitates and their impacts on the microstructures in their surrounding BaTiO¬3-rich matrix. Also, the response of ferroelectric domains around CaTiO3-rich precipitates during heating and cooling is observed in-situ with transmission electron microscopy. Domains attached to precipitates are observed remaining unchanged up to the Curie point at which they disappear. During cooling, domains are observed to form in the vicinity of precipitates and being held in place down to room temperature. Both observations corroborate previous findings that precipitates act as domain pinning points, behaving in a similar manner to earlier experiments with electrical field biasing. Dislocations are often seen around precipitates in the matrix grain and are observed interfering with domains during heating cycles. Dislocations may provide an additional mechanism to restrict domain wall motion and offer a greater piezoelectric hardening effect. 

Precipitates have recently been found to significantly enhance the mechanical quality factor in piezoelectric ceramics. Such a piezoelectric hardening effect was attributed to strong interactions between ferroelectric domains and precipitates. In the present work, the response of domains to applied electric fields is observed in situ via transmission electron microscopy in aged (Ba, Ca)TiO3 ceramics with precipitates to reveal the underlying mechanism of this phenomenon. Ferroelectric domains in the Ba-rich matrix grain are observed to be more concentrated near non-polar Ca-rich precipitates. With increasing applied voltage, domains separate from precipitates merge together first, while those near precipitates persist to higher voltages. During ramping down, domains nucleate from precipitates. These direct observations confirm the strong interactions between ferroelectric domains and precipitates in piezoelectric ceramics.