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arXiv · 1706.08963

Electrocaloric effects in the lead-free Ba(Zr,Ti)O$_{3}$ relaxor ferroelectric from atomistic simulations

Zhijun Jiang·Sergei Prokhorenko·Sergey Prosandeev·Y. Nahas·D. Wang·J. Íñiguez·E. Defay·L. Bellaiche
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Abstract

Atomistic effective Hamiltonian simulations are used to investigate electrocaloric (EC) effects in the lead-free Ba(Zr$_{0.5}$Ti$_{0.5}$)O$_{3}$ (BZT) relaxor ferroelectric. We find that the EC coefficient varies non-monotonically with the field at any temperature, presenting a maximum that can be traced back to the behavior of BZT's polar nanoregions. We also introduce a simple Landau-based model that reproduces the EC behavior of BZT as a function of field and temperature, and which is directly applicable to other compounds. Finally, we confirm that, for low temperatures (i.e., in non-ergodic conditions), the usual indirect approach to measure the EC response provides an estimate that differs quantitatively from a direct evaluation of the field-induced temperature change.

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Zhijun Jiang, Sergei Prokhorenko, Sergey Prosandeev, Y. Nahas, D. Wang, J. Íñiguez, E. Defay, L. Bellaiche. 2017-06-27. Electrocaloric effects in the lead-free Ba(Zr,Ti)O$_{3}$ relaxor ferroelectric from atomistic simulations. https://doi.org/10.1103/physrevb.96.014114

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