Nanoscale Heat Conduction Across Metal-Dielectric Interfaces

Abstract

We report a theoretical study of heat conduction across metal-dielectric interfaces in devices and structures of practical interest. At cryogenic temperatures, the thermal interface resistance between electrodes and a substrate is responsible for substantial reduction in the maximum permissible peak power in Josephson junctions. The thermal interface resistance is much smaller at elevated temperatures but it still plays a critical role in nanoscale devices and structures, especially nanolaminates that consist of alternating metal and dielectric layers. A theoretical model is developed to elucidate the impact of spatial nonequilibrium between electrons and phonons on heat conduction across nanolaminates. The diffuse mismatch model is found to provide reasonable estimates of the intrinsic thermal interface resistance near room temperature as well as at cryogenic temperatures.

Measurement and evaluation of the interfacial thermal resistance between a metal and a dielectric

“…The third effect is describable with a continuum two-fluid model. 11,12 These three causes reasonably coexist; inelastic scattering between electrons in metal and phonons in dielectric is rarely considered in previous literatures due to its insignificant effect, as for the thermal resistances caused by phonon-phonon scattering at the interface and by electron-phonon nonequilibrium near the interface in metal, Majumdar and Reddy 12 suggested that they are in series. In this work, we used a sandwiched film structure, which an ultrathin pure metal layer is sandwiched between two dielectric layers, to calculate the theoretical value by using a continuum two-fluid model and also to measure the metal-dielectric interfacial thermal resistance.…”

Heat diode effect and negative differential thermal conductance across nanoscale metal-dielectric interfaces

“…When considering the pathway (2), one usually applies the phenomenological two-temperature model [13] that has been widely used to investigate the ultrafast pulsed laser heating of metals [14,15], and assume the pathway (3) is negligible [8,9]. However, when the imperfect interface or the large lattice-mismatch of metal and dielectric is present, both pathway (1) and (2) will be seriously suppressed and the pathway (3) becomes significant.…”

“…Hence, for metal-dielectric interfacial heat transport, energy transfer includes three possible pathways: (1) energy exchange between phonons in metal and phonons in dielectric, which is widely studied with the acoustic and diffuse mismatch models [3][4][5][6]; (2) nonequilibrium electron-phonon (e-ph) energy exchange within the metal, with subsequently phonon-phonon coupling across the interface [7][8][9]; (3) direct energy transfer from electrons in metal to phonons in dielectric through inelastic scattering induced by e-ph coupling across the interface [10][11][12].…”

Ultrafast Magnetization Dynamics of SrRuO₃Thin Films

“…It has been suggested that there is an effective boundary resistance due to nonequilibrium between different temperature baths in a region near the film/substrate interface [60,39]. The non-equilibrium region is a result of different boundary conditions for the different baths.…”