Synthesis, characterization, and electrical properties of Nd 3+ ‐doped (Bi 0.4 Na 0.2 K 0.2 Ba 0.2 )TiO 3 high‐entropy ceramics

Abstract Recently, high‐entropy perovskites have attracted considerable attention due to their diverse chemical composition and multifunctionality. In this study, the high‐entropy approach was employed in a (Bi 0.4 Na 0.2 K 0.2 Ba 0.2 )TiO 3 matrix, and Nd 3+ was introduced to enhance the configurational entropy and modify its dielectric and ferroelectric properties. Notably, despite Nd 3+ doping, all samples maintained a tetragonal perovskite structure at room temperature. The configurational entropy increased with the Nd 3+ concentration, consequently leading to a gradual decline in the ferroelectric properties along with the associated temperature ( T m ) and maximum dielectric constant ( ε m ). The P – E loops of the ceramics also became thinner as P m and P r decreased, resulting in a slow decrease in the recoverable energy density ( W rec ) and a simultaneous increase in the energy storage efficiency ( η ). Especially, the energy storage performance reached its peak at an Nd 3+ concentration of 12 mol%, exhibiting an energy storage efficiency of 85.8% and a recoverable energy storage density of 0.74 J/cm 3 at a low electric field of 100 kV/cm. These results highlight the potential of this material for dielectric applications in low electric fields and contribute to the advancement of alternative high‐entropy energy storage perovskite ceramics.