Time-resolved thermal transport in compositionally modulated metal films

Thermal transport through thin films: Mirage technique measurements on aluminum/titanium multilayers

“…The interface resistance ρ = 2.1 × 10 -6 cm 2 · K· W -1 is nearly identical to the value 10 -6 cm 2 · K· W -1 obtained for YSZ/SiO 2 interfaces in multilayers [10]. It is approximately an order of magnitude smaller than values obtained from metal/metal multilayers at room temperature [8] as well as upper bound values obtained at elevated temperatures [7,9]. It is between one and two order of magnitude smaller than the range of values, between 4 × 10 -4 and 5 × 10 -5 cm 2 · K· W -1 , obtained at room temperature for metal/dielectric interfaces from thin film experiments [31] (values published as interface, or Kapitza, conductance, which equals ρ -1 ).…”

“…Whether that thermal energy is carried by electrons or phonons and whether it is scattered specularly, diffusely, or some combination of both at the interface is not addressed here; the interface thermal resistance ρ represents the cumulative impact of the scattering phenomena on thermal conductivity normal to the interface. Assuming ρ to be 10 -5 to 10 -6 cm 2 · K· W -1 [7][8][9][10] and using the data in Fig. 3, the grain size t is calculated to be approximately 3 µm to 0.3 µm.…”

“…A comprehensive examination of the latter effect can be found in review articles by Swartz and Pohl [5] and Cahill [6]. Some researchers have measured the interface resistance by studying the thermal transport properties of metal/metal [7,8], metal/oxide [9], oxide/oxide [10] or semiconductor/semiconductor [11,12,13,14,15,16] multilayer films. Unlike techniques using single layer films, experiments using multilayers can separate interface effects from those due to total film thickness, e.g.…”

“…By studying films with a range of bilayer thickness, it has been possible to systematically examine the effect of the interfaces on the anisotropic thermal diffusivity. Most of the cited studies used techniques that restricted their measurements to in-plane thermal diffusivities, though a few used transient reflection [8,16] or transmission techniques [7,9], or simplified mirage [12] that were limited to studying the diffusivity normal to the film surface. The Mirage technique utilized here is capable of measuring the thermal diffusivity at room temperature in both the normal and in-plane directions.…”

Thermal boundary conductance of transition metals on diamond

“…In this paper, the link between adhesion of a metallic layer on diamond and TBC between the former and the latter is emphasized. TDTR has long been used successfully to measure the TBC of interfaces in metal/metal (Clemens et al, 1988;Gundrum et al, 2005) or metal/dielectric systems (Hopkins et al, 2007;Hopkins et al 2008;Lyeo and Cahill 2006;Stevens et al, 2005;Stoner and Maris 1993). This technique has the advantage to offer insight on nanometer-scale thermal diffusion effects, and thus is able to isolate the in uence of a single interface on conductivity (Cahill et al, 2002.…”