2014/05/30 by Madhura Marathe, Claude Ederer · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci
paper · pdf · doi:10.1063/1.4879840
published as Appl. Phys. Lett. 104, 212902 (2014)
arxiv created 2014/05/30 · arxiv updated 2014/06/02
We address the question of how the electrocaloric effect in epitaxial thin films of the prototypical ferroelectric BaTiO3 is affected by the clamping to the substrate and by substrate-induced misfit strain. We use molecular dynamics simulations and a first-principles-based effective Hamiltonian to calculate the adiabatic temperature change ΔT under different epitaxial constraints. Our results demonstrate that, consistent with phenomenological theory, clamping by the substrate reduces the maximum ΔT compared to bulk BaTiO3. On the other hand, compressive misfit-strain leads to a strong increase of ΔT and shifts the maximum of the electrocaloric effect to higher temperatures. A rather small compressive strain of -0.75% is sufficient to obtain a ΔT that is larger than the corresponding bulk value.