Effect of modulating monovalent ion doped on A-site high-entropy perovskites.

High-entropy materials constitute solid solutions composed of five or more elements. This complex and diverse composition endows the materials with unique physical and chemical properties, presenting immeasurable value in material design. Despite such potential applications, the composition design still has deficiencies, and the influence mechanism of elements remains a research gap. In this work, a series of new high-entropy perovskites (La 0.5 X 0.5) 0.2 (Ce 0.5 X 0.5) 0.2 Ba 0.2 Sr 0.2 Ca 0.2 TiO 3 (where X = Li, Na, K) were designed and synthesized. We systematically studied their phase structures, microscopic morphologies, as well as dielectric and ferroelectric properties. Notably, novel findings are reported. Specifically, (La 0.5 Li 0.5) 0.2 (Ce 0.5 Li 0.5) 0.2 Ba 0.2 Sr 0.2 Ca 0.2 TiO 3 ceramics exhibit excellent breakdown field strength (E b = 135 kV cm−1) and minimal leakage currents in 10−7–10−6 A cm−2. Moreover, the designed ceramics display exceptional dielectric constant (ε r = 5 × 104) and saturation polarization (P s = 2.8 μC cm−2) properties. These findings introduce novel insights into designing high-entropy ceramic components, enabling the customization of new dielectric and ferroelectric properties by manipulating doped monovalent ions. [ABSTRACT FROM AUTHOR]