Microstructure and dielectric properties of high-entropy Sr0.9La0.1MeO3 (Me: Zr, Sn, Ti, Hf, Mn, Nb) perovskite ceramics

Abstract

Entropy engineering has attracted extensive attention, which is applied to induce controllable changes in structures through lattice distortion effects to optimize certain properties. In this work, a series of pure phase high-entropy dielectric ceramics, Sr0.9La0.1MeO3 (Me = Zr, Sn, Ti, Hf, Mn, Nb) were synthesized at the sintering temperature of 1550 °C via a traditional solid phase method. The internal relationship between phase stability and dielectric properties with respect to the variation of mixing entropy were investigated. The distortion of oxygen octahedron (in-phase and antiphase) and antiparallel cation displacement were produced in Sr0.9La0.1(Zr0.25Sn0.25Ti0.25Hf0.25)O3 (4M) ceramic system after the introduction of four cations into B-site. Finally, 4M ceramic possesses excellent dielectric permittivity frequency stability and dielectric-temperature stability (εr/ε25°C<5% within −100 to 300 °C) with a low dielectric loss (<0.01). This work provides a valuable reference for entropy engineering to control dielectric performance and phase stability, and may facilitate the discovery and design of novel electronic ceramics.

Keywords

• High-entropy ceramics
• Perovskite phase
• Dielectric properties