The electrocaloric effect in BaTiO${}_3$ at all three ferroelectric transitions: anisotropy and inverse caloric effects

Abstract

We study the electrocaloric (EC) effect in bulk BaTiO${}_3$ (BTO) using molecular dynamics simulations of a first principles-based effective Hamiltonian, combined with direct measurements of the adiabatic EC temperature change in BTO single crystals. We examine in particular the dependence of the EC effect on the direction of the applied electric field at all three ferroelectric transitions, and we show that the EC response is strongly anisotropic. Most strikingly, an inverse caloric effect, i.e., a temperature increase under field removal, can be observed at both ferroelectric-ferroelectric transitions for certain orientations of the applied field. Using the generalized Clausius-Clapeyron equation, we show that the inverse effect occurs exactly for those cases where the field orientation favors the higher temperature/higher entropy phase. Our simulations show that temperature changes of around 1 K can in principle be obtained at the tetragonal-orthorhombic transition close to room temperature, even for small applied fields, provided that the applied field is strong enough to drive the system across the first order transition line. Our direct EC measurements for BTO single crystals at the cubic-tetragonal and at the tetragonal-orthorhombic transitions are in good qualitative agreement with our theoretical predictions, and in particular confirm the occurrence of an inverse EC effect at the tetragonal-orthorhombic transition for electric fields applied along the [001] pseudo-cubic direction.

12 pages, 11 figures

References in corpus (6)

• Advanced materials for solid-state refrigeration
• First principles-based calculation of the electrocaloric effect in BaTiO${}_3$: comparison between direct and indirect methods
• First-principles accurate total-energy surfaces for polar structural distortions of BaTiO3, PbTiO3, and SrTiO3: consequences to structural transition temperatures
• Influence of defects on ferroelectric and electrocaloric properties of BaTiO${}_3$
• Positive and negative electrocaloric effect in BaTiO${}_3$ in the presence of defect dipoles
• Electrocaloric effect in BaTiO${}_3$: a first-principles-based study on the effect of misfit strain

Cited by in corpus (16)

• Electric field induced phase transition and electrocaloric effect in PMN-PT
• Origin of the Large Negative Electrocaloric Effect in Antiferroelectric PbZrO3
• Giant electrocaloric response in the prototypical Pb(Mg,Nb)O${}_3$ relaxor ferroelectric from atomistic simulations
• Giant Direct and Inverse Electrocaloric Effects in Multiferroic Thin Films
• Polarization rotation and the electrocaloric effect in barium titanate
• Tailoring the electrocaloric effect by internal bias fields and field protocols
• The impact of hysteresis on the electrocaloric effect at first-order phase transitions
• Size-Induced High Electrocaloric Response of Dense Ferroelectric Nanocomposites
• Domain Wall Acceleration by Ultrafast Field Application: An Ab Initio-Based Molecular Dynamics Study
• Origin of negative electrocaloric effect in Pnma-type antiferroelectric perovskites
• Enhancement of electrocaloric response through quantum effects
• Impact of domains on the orthorhombic-tetragonal transition of BaTiO${}_3$: an ab initio study
• Thermal stability of nano-scale ferroelectric domains by molecular dynamics modeling
• Negative electrocaloric effect in nonpolar phases of perovskite over wide range of temperature
• Electric field direction dependence of the electrocaloric effect in BaTiO3
• Point defect design in (Ba,Sr)TiO${}_3$ -- an insight on agglomeration