Electrocaloric Performance of High-Entropy Oxides from First Principles

The electrocaloric effect holds significant promise for advancing sustainable solid-state refrigeration technologies. High-entropy oxides [1] are potentially advantageous due to the thermal stability of their polar phases. In this work, we evaluate the phase stability and electrocaloric performance of the high-entropy perovskite (Na,Bi,Sr,Ba,Ca)TiO₃. A pivotal parameter in evaluating electrocaloric performance is the dependence of adiabatic electrocaloric temperature change as a function of temperature, which is intricately linked to the change of polarization with respect to temperature under a constant electric field [3]. To predict this parameter, we developed models for the temperature-dependent polarization <i>P</i>(<i>T</i>) of high-entropy oxides taking into account chemical disorder and local distortions.<br/><br/>[1] Rost <i>et al.</i>, <i>Nature Communications</i> <b>6</b>, 8485 (2015)<br/>[2] Kotsonis et al., <i>Journal of the American Ceramic Society</i> <b>106</b>, 5587 (2023)<br/>[3] Nair <i>et al</i>., <i>Nature</i> <b>575</b>, 468–472 (2019)<br/><br/><b>Funding:</b> The Center for Nanoscale Science at the Pennsylvania State University is a Materials Research Science and Engineering Center (MRSEC) supported by the National Science Foundation (DMR-2011839)