Mechanical Controlled Thermal Switch and Hysteresis with Domain Boundary Engineered Phonon Transport

TL;DR

This paper introduces a mechanical method to control thermal conductivity in materials by manipulating domain boundaries, enabling thermal switching and hysteresis effects for energy applications.

Contribution

It presents a novel domain boundary engineering approach to mechanically tune phonon transport and thermal properties in materials.

Findings

External stress alters twin boundary density, modulating thermal conductivity.

Twin boundaries scatter phonons, affecting heat flow inversely.

Mechanical control induces hysteresis in thermal conductivity.

Abstract

Heat flow control in phononics has received significant attention recently due to its widespread applications in energy transfer, conversion and utilization. Here, we demonstrate that by applying external stress or strain we can effectively tune the thermal conductivity through changing the density of twin boundaries, which in turn offers the intriguing mechanical-controlled thermal switch and hysteresis operations. Twin boundaries perpendicular to the transport direction strongly scatter phonons. As such, the heat flow is in inverse proportional to the density of twin boundaries and hence allows an excellent way to switch thermal conductivity mechanically and even leads to the interesting hysteresis behavior as a thermal memory. Our study provides a novel mechanism to couple thermal and mechanical properties of materials as a matter of "domain boundary engineering" and can have substantial implications in flexible thermal control and thermal energy harvesting.