An atomistic effective Hamiltonian technique is used to investigate the finite-temperature energy storage properties of a ferroelectric nanocomposite consisting of an array of BaTiO3 nanowires embedded in a SrTiO3 matrix, for electric field applied along the long axis of the nanowires. We find that the energy density \textit{versus} temperature curve adopts a nonlinear, mostly temperature-independent response when the system exhibits phases possessing an out-of-plane polarization and vortices while the energy density more linearly increases with temperature when the nanocomposite either only possesses vortices (and thus no spontaneous polarization) or is in a paraelectric and paratoroidic phase for its equilibrium state. Ultrahigh energy density up to ≃140 J/cm3 and an ideal 100% efficiency are also predicted in this nanocomposite. A phenomenological model, involving a coupling between polarization and toroidal moment, is further proposed to interpret these energy density results.
@article{arxiv.2305.14099,
title = {Energy storage properties of ferroelectric nanocomposites},
author = {Zhijun Jiang and Zhenlong Zhang and Sergei Prokhorenko and Yousra Nahas and Sergey Prosandeev and Laurent Bellaiche},
journal= {arXiv preprint arXiv:2305.14099},
year = {2023}
}