Berlin 2024 – scientific programme
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DS: Fachverband Dünne Schichten
DS 21: Optical Analysis of Thin Films
DS 21.7: Talk
Friday, March 22, 2024, 11:30–11:45, A 053
Thermal conductivitiy of hard-metal thin films microscopically resolved by Brillouin scattering — •Nils Denkmann1, Donita Delijaj1, Lasse Leukefeld1, Nelson Filipe Lopes Dias2, Finn Ontrup2, Wolfgang Tillmann2, and Jörg Debus1 — 1Department of Physics, TU Dortmund — 2Institute of Materials Engineering, TU Dortmund
Common procedures to measure the thermal conductivity of thin films are, e.g., the differential scanning calorimetry or the transient thermoreflectance. These methods predominantly provide macroscopic values and are not applicable to samples with complex geometries. To determine the thermal conductivity with micrometer spatial resolution and independently of the sample geometry as well as to understand the nanoscopic mechanisms alternative methods are needed. Here, we show how acoustic surface waves inside hard-metal thin films (e.g., TiAlN) are examined directly using Brillouin laser-light scattering. This method allows us to determine the thermal conductivity as function of the waves' propagation direction and the shear/Young's modulus. Spatial scanning is moreover exploited to correlate our microscopic acquisition with complementary macroscopic data. The results will provide a thorough insight into the effects of thermo-mechanical properties of hard-metal thin films.
Keywords: Brillouin scattering; hard-metal films; thermal conductivity; thermal-mechanical stress