The concept of entropy stabilization has recently attracted attention in materials science research due to potential unexpected properties caused by a random distribution of species in crystalline structures. This study explores chemical disorder in the case of high entropy perovskites, by incorporating at least five randomly distributed cations on A-site crystallographic cationic site.
(Bi0.2K0.2Ba0.2Sr0.2Ca0.2)TiO3 powders were prepared by a wet-chemical method. The composition, thermal stability, and morphology of the nanoparticles were investigated. Processing powders at temperatures between 900 and 1000°C leads to a mixture of polymorphic phases. The particles processed in these conditions show a polyhedral-shaped morphology and sizes between 10 and 16 nm.
The powders were consolidated by alternative routes. Classical and spark plasma sintered ceramics showed the desired composition when processed at temperatures between 900-1000°C. The average grain size depended on the sintering route and the processing temperature and ranged between 17 to 50 nm.
The dielectric behavior of the obtained ceramic materials suggests a relaxor-type behavior, with a temperature and frequency-dependent permittivity maximum.
 
Acknowledgement: This work was supported by a grant of Ministry of Research, Innovation and Digitization, CNCS-UEFISCDI, project number PN-III-P1.1-PD-2021-0625, within PNCDI III