Flexocaloric effect in ceramics

Abstract

The strain gradient-driven caloric component or flexocaloric effect (FCE) can be obtained in any material, enabling a higher working temperature or above Curie temperature. The FCE uses an inhomogeneous deformation of the crystal lattice to produce polarization (FCE). The flexopolarization coefficient obtained due to strain gradient is used to calculate FCE. Numerous FCE evaluation methods are available based on measured qualities and their combinations. Thermodynamic relations, Maxwell’s relations, Landau–Ginzburg method, Electrocaloric approach, cross-coupling relation, and elastocaloric relation are explored to evaluate FCE and discussed in this chapter. The electrical field-induced stress gradient field-based converse or inverse FCE is also evaluated. The FCE potential in BaTiO3-based ceramic, thin film ceramic, lead-based ceramic, and functionally graded materials ceramics are elaborated. Finally, the possibility of the inverse caloric effect will also be discussed. © 2024 Elsevier Ltd. All rights reserved.