Strengthened dielectric relaxation and energy efficiency of Bi(Mg0.5Hf0.5)O3-doped Ba(Ti0.8Sn0.2)O3 ceramics

Bi(Mg 0.5 Hf 0.5 )O 3 (BMH) has been frequently exploited to engineer the material’s phase structure, micromorphology, dielectric, piezoelectric, and energy storage performance of BaTiO 3 (BT)-based ceramics for the optimization of multifunctional dielectrics. Herein, combined with the Ba(Ti 0.8 Sn 0.2 )O 3 relaxor, (1 –  x )Ba(Ti 0.8 Sn 0.2 )O 3 – x Bi(Mg 0.5 Hf 0.5 )O 3 (BTS- x BMH) ceramic samples were prepared through a solid-state reaction process. The micromorphology, dielectric properties, ferroelectric properties, and energy storage performance of BTS- x BMH ceramics were engineered by increasing BMH content. The addition of BMH can refine the grain size, increase the relaxation degree, raise the breakdown strength, and facilitate the production of the polar nanoregions in the BTS- x BMH ceramics. Compared to pure BTS, the energy efficiency of BTS-BMH is remarkably enhanced, which originates from the disruption of the ferroelectric long-range order owing to the BMH modification. At the maximum applied field of 100 kV/cm, the largest energy density of W rec  = 0.3 J/cm 3 was realized at the composition of x  = 0.05. The highest energy efficiency of η  = 99% was acquired for x  = 0.15 at 110 kV/cm. Moreover, the energy efficiency for x  = 0.15 displays good temperature stability. These findings can guide the further optimization design of environmentally friendly BT-based ceramic capacitors for energy storage applications.