Anisotropy-driven thermal conductivity switching and thermal hysteresis in a ferroelectric

TL;DR

This paper proposes a theoretical design for a thermal switch utilizing the anisotropic thermal conductivity of PbTiO3, controllable via electric field-induced ferroelectric polarization rotation, with potential high-frequency operation.

Contribution

It introduces a novel thermal switch concept based on ferroelectric polarization rotation and thermal conductivity anisotropy, supported by phonon Boltzmann Transport Equation calculations.

Findings

Thermal conductivity exhibits hysteresis with electric field.

Switching response time is limited by ferroelectric switching speed.

High-frequency operation of the thermal switch is feasible.

Abstract

We present a theoretical proposal for the design of a thermal switch based on the anisotropy of the thermal conductivity of PbTiO3 and of the possibility to rotate the ferroelectric polarization with an external electric field. Our calculations are based on an iterative solution of the phonon Boltzmann Transport Equation and rely on interatomic force constants computed within an efficient second-principles density functional theory scheme. We also characterize the hysteresis cycle of the thermal conductivity in presence of an applied electric field and show that the response time would be limited by speed of the ferroelectric switch itself and thus can operate in the high-frequency regime.