Dielectric Relaxation Behavior of (Bi0.2Na0.2Ba0.2Sr0.2Ca0.2)TiO3 High-Entropy Ceramic

Abstract

High entropy materials are a relatively young new class of materials discovered in 2003. It possesses four kinds of special core effects as a result of its strong mixing nature such as (i) High entropy effect, (ii) Severe lattice distortion effect, (iii) Sluggish diffusion effect, and (iv) Cocktail effect. High Entropy Ceramics (HECs) are defined as the solid solutions of inorganic compounds (five or more cations sublattices) with one or more Wykoff sites shared by equal or nearly equal atomic ratios of multi-principal elements. HECs have gained the attention of researchers due to their fascinating properties. In this report, an A-site disordered high entropy perovskite (Bi_0.2Na_0.2Ba_0.2Sr_0.2Ca_0.2)TiO₃ ceramic was prepared via a solid-state reaction route. The XRD pattern and FESEM-EDS confirmed the formation of a single-phase solid solution with a tetragonal structure. A detailed study of the dielectric behavior of the sample was done. Modified Curie-Weiss law was fitted to the relative permittivity to analyze the relaxor behavior of the sample. HECs are highly tolerant to ions and their properties can be tailored by composition and according to the application purposes.