Electrocaloric and Pyroelectric Properties of Ferroelectric Films

We use a non-linear thermodynamic model to investigate the electrocaloric and pyroelectric response of thin film perovskite ferroelectrics under the influence of differing electrical, thermal and mechanical boundary conditions including bias and driving field, temperature, lateral clamping, and misfit strain. A comparison of ferroelectric solid solutions comprised of BaTiO$_{3}$, PbTiO$_{3}$ and/or SrTiO$_{3}$ illustrates the influence of composition and lateral clamping effect on the electrocaloric properties. The theoretical analysis of a variety of ferroelectric thin films on IC-friendly substrates such as Si and sapphire shows that the room temperature dielectric and electrothermal responses of these films depend strongly on the synthesis/processing temperature$.$ These combined results provide insights concerning how the deposition temperature, substrate material and composition can be adjusted to obtain desired electrothermal properties.