Phase-field simulation of electrocaloric effect in textured Ba_0.8Sr_0.2TiO₃ polycrystalline ceramics

Textured ceramics exhibit a reduced coercive field, and when aligned in the same direction as the spontaneous polarization, they enhance the adiabatic temperature change (∆T) of the material. In this paper, we employ a polycrystalline phase-field model to analyze the solid solution Ba_0.8Sr_0.2TiO₃ (BST80) with a <001> orientation, alongside randomly oriented polycrystals, aiming to investigate the influence of texturing on the electrocaloric effect (ECE) performance. We examine six distinct groups characterized by varying grain orientation angles for the randomly oriented polycrystals for hysteresis loop calculations. Utilizing Maxwell's relations, we compute the ECE for the randomly oriented BST80 polycrystal and the <001>-textured BST80 polycrystal across different electric field strengths. The findings indicate that the ∆T achieved with the <001>-textured BST80 polycrystal surpasses that of the randomly oriented BST80 polycrystal. Furthermore, the temperature at which the maximum ∆T occurs for the <001>-textured BST80 polycrystal is observed to be shifted to higher values compared to the randomly oriented variant. The observed enhancement of ECE in BST80 polycrystalline ceramics due to texturing offers valuable insights and foundational knowledge for future theoretical and experimental investigations.