On the thermodynamic foundations of solid-state cooler based on multiferroic materials

• Development of theoretical foundations for the design of multiferroic refrigerator.
• Derivation of the heat conduction equation for multiferroic materials.
• Evaluation of the temperature of the multiferroic structure under external fields.
• Analysis of the coordinate temperature dependence of the multiferroic composite.

In this work, we present the theoretical description of thermodynamics of the solid-state cooler based on multiferroic materials. By virtue of the derived equations, we examine the temperature dependence of multiferroic with simultaneous exposure to the periodic electric, magnetic, and elastic fields. The presence of heat exchange with the environment is taken into account. It is demonstrated that the modulation of the applied electric field by magnetic and/or elastic ones can increase the temperature change in 2–3 times in comparison with just the electric field contribution. Additionally, the paper pays careful attention to the layered multiferroic structure. The temperature distribution of this system as a function of position is investigated. The obtained results provide a theoretical basis and physical insights for further development of the efficient solid-state cooler based on multiferroic materials.