Giant electro-induced strain in lead-free relaxor ferroelectrics via defect engineering

Effect of La substitution on energy storage properties of (Bi0.2Na0.2Ca0.2Ba0.2Sr0.2)TiO3 lead‐free high‐entropy ceramics

“…[24][25][26][27] Xu et al reported that [(Bi 0.5 Na 05 ) 0.93 Ba 0.07 ] 1-x La x TiO 3 ceramics exhibited compact microstructures with fine grains and that the breakdown field strength drastically improved by La doping, resulting in a maximum W rec of 1.21 J/cm 3 for 0.04La sample. 25 Liu et al 26 revealed that the grain size of La-doped Na 0.3 Bi 0.3 Sr 0.4 TiO 3 significantly reduced, thus increasing the E b , and the obtained Na 0.3 Sr 0.4 Bi 0.3 TiO 3 -0.02La ceramic displayed high W rec (1.67 J/cm 3 ) and E b (190 kV/cm). Li et al synthesized lead-free La-substituted 0.72Na0.5Bi0.5TiO3-0.28Sr0.7Bi0.2TiO3 and showed that La addition effectively decreased the grain size and generated a large E b , achieving the optimum W rec (1.2 J/cm 3 ) for 0.005La-substituted ceramic under an E b of 90 kV/cm.…”

“…As the core components of high/pulsed-power electronic devices, dielectric ceramic capacitors with high power densities, high voltage resistance, and excellent thermal stability have received significant attention in the manufacture of advanced electronic equipment. [1][2][3] However, their relatively low recoverable energy storage density (W rec ) and energy efficiency (η) greatly limit their practical applications. Generally, the energy storage performance of ceramics can be evaluated based on the electric field hysteresis loop and the following equations:…”

“…selected NaNbO 3 and La 3+ as chemical modifiers to optimize the relaxation degree of BaTiO 3 -Bi 0.5 Na 0.5 TiO 3 ceramics, which effectively increased the energy storage properties (W rec ∼ 1.24J/cm 3 , η ∼ 96%). 10 In recent years, the concept of high-entropy ceramics (HECs) has received a lot of attention in dielectric ceramics and offers more opportunities for regulating performance strategy.…”

“…20 Fang et al incorporated MnCO 3 into (Na 0.2 Bi 0.2 Ca 0.2 Ba 0.2 Sr 0.2 )TiO 3 HECs to enhance the insulation resistance, resulting in a high E b of 160 kV/cm and a W rec of 1.56 J/cm. 21 In our previous study, (Na 0.2 Bi 0.2 Ca 0.2 Ba 0.2 Sr 0.2 )TiO 3 HECs were synthesized using the hydrothermal method, which presented a large degree of lattice distortion and afforded high W rec (1.37 J/cm 3 ) and E b (127 kV/cm). 22 In these studies, although the HECs demonstrated energy storage performance, the relatively low E b inhibited the improvements to the energy storage properties.…”

“…In general, some microstructural factors are crucial in optimizing the breakdown electric field, such as secondary phases, grain size, density, bandgap, and core–shell structures 3 . Among these features, the grain size ( G ) significantly affects the E b of ceramics, as indicated by the following relationship 23 : $$$$\begin{equation}{E}_{\mathrm{b}} \propto {}^{1}/_{\!\!\sqrt{G}}.\end{equation}$$$$…”