Large Thermal Conductivity Switching in Ferroelectrics by Electric Field-Triggered Crystal Symmetry Engineering

Abstract

A convenient, reversible, fast, and wide-range switching of thermal conductivity is desired for efficient heat energy management. However, traditional methods, such as temperature-induced phase transition and chemical doping, have many limitations, e.g., the lack of continuous tunability over a wide temperature range and low switching speed. In this work, a strategy of electric field-driven crystal symmetry engineering to efficiently modulate thermal conductivity is reported with first-principles calculations. By simply changing the direction of an external electric field loaded in ferroelectric PbZr0.5Ti0.5O3, near the morphotropic phase boundary composition, we obtain the largest switching of thermal conductivity for ferroelectric materials at room temperature based on the dual-phonon theory, i.e., normal and diffuson-like phonons, with three different criteria. The calculation results indicate that with decreasing crystal symmetry, the degeneracy of phonon modes reduces and the avoid-crossing behavior of phonon branches enhances, leading to the increase of diffuson-like phonons and weighted phonon–phonon scattering phase space. A thermal switch prototype based on PbZr0.5Ti0.5O3 is further shown that can protect the Li-ion battery by modulating its temperature up to 17.5 °C. Our studies would pave the way for designing next-generation thermal switch with high speed, a wide temperature range, and a large switching ratio.

Intervalley scattering induced significant reduction in lattice thermal conductivities for phosphorene

“…Actually, studies have shown that symmetry breaking can significantly reduce the phonon degeneracy and enhance the avoid-crossing behavior of phonon branches, which results in an increase in the phonon-phonon scattering phase space to limit lattice heat transport. 26,27 The optimized lattice constants are 3.28 Å and 4.12 Å for b-P and b-Sb, respectively, which are in good agreement with the previous work. 28,29 The calculated band structures are shown in Fig.…”

Thermal conductivity of sliding bilayer h-BN and its manipulation with strain and layer confinement

“…The switching of electrical polarization is usually driven by the external forces, for example an external electric field. 3,[9][10][11] The experimentally controllable sliding on bilayer h-BN, breaking the lattice symmetry, implies a high potential of modulation of lattice thermal conductivity in such an exotic low-dimensional system.…”

Electric-controlled tunable thermal switch based on Janus monolayer MoSSe

“…As an excellent reversible nondestructive thermal transport regulation method, electric field has great potential to be used for realizing thermal switches, which has been verified in the fluid-based thermal diodes 41,42 . However, researches on the solid-state thermal switches driven by the electric field are rare, and are mainly limited in ferroelectric materials [43][44][45] , where the "on" and "off" states In this work, we systematically studied the thermal transport properties of Janus monolayer MoSSe with external electric field applied. It is shown that the thermal transport in Janus monolayer MoSSe exhibits significant adjustability that the thermal conductivity reaches 2.13 times the pristine value under an electric field of 0.040 VÅ −1 applied from S to Se atom.…”