Enhancement of interface thermal conductance between Cr-Ni alloy and dielectric via Cu nano-interlayer

Facilitating interfacial thermal transport is highly desirable for various engineering applications, such as improving heat dissipation in microelectronics and efficiency of electrothermal heating element. Here, the interface thermal conductances (ITCs) of Cr_0.22Ni_0.78/MgO and Cr_0.22Ni_0.78/Al₂O₃interfaces are studied through the non-equilibrium molecular dynamics simulation. It is found that the two ITCs can be hugely enhanced by 3 and 2.4 times, respectively, with the introduction of Cu nano-interlayer of a thickness larger than 7.2 Å. The enhanced ratio is robust and shows weak dependence on temperature. Further vibrational spectral analysis and phonon transmission function reveal that the enhancement in ITC mainly originates from the boosting of inelastic phonon scattering, which is generally considered to contribute a small proportion to ITC. Here, the inelastic scattering contributes as high as 63% to the ITC of Cr_0.22Ni_0.78/Cu/MgO interface at 300 K. The findings provide an effective strategy to enhance ITC at a wide temperature range and advance our understanding of inelastic scattering in interfacial phonon transport.