Phys.org November 4, 2024 As metallic nanostructures shrink towards the size of the electronic mean free path, thermal conductivity decreases due to increased electronic scattering rates. Matthiessen’s rule is commonly applied to assess changes in electron scattering rates, although this rule has not been validated experimentally at typical operating temperatures for most of the electronic systems. A team of researchers in the US (University of Virginia, University of Rhode Island, Oak Ridge National Laboratory, Intel Corporation) experimentally evaluated the validity of Matthiessen’s rule in determining the thermal conductivity of thin metal films by measuring the in-plane thermal conductivity and electronic […]
Tag Archives: thermal conductivity
Researchers tune thermal conductivity of materials ‘on the fly’ for more energy-efficient devices
Phys.org June 8, 2923 A team of researchers in the US (University of Minnesota, University of Utah, Argonne National Laboratory) demonstrated the ability to continuously tune the thermal conductivity of nanoscale films of La0.5Sr0.5CoO3-δ (LSCO) by a factor of over 5, via a room-temperature electrolyte-gate-induced non-volatile topotactic phase transformation from perovskite to an oxygen-vacancy-ordered brownmillerite phase accompanied by a metal-insulator transition. Combining time-domain thermoreflectance and electronic transport measurements, model analyses based on molecular dynamics and Boltzmann transport equation, and structural characterization by X-ray diffraction, they uncovered and deconvolved the effects of these transitions on heat carriers, including electrons and lattice […]
Chaos that will keep you warm: Researchers improve heat insulation using deliberate chaos
Science Daily March 31, 2018 Thermal conductivity of well-ordered crystal structure is low. Researchers in Germany produced nanoparticles which exhibit a thermal conductivity that is even much lower. These materials are mixtures in powder form: crystalline order is thus replaced with chaos. They found that the highest insulation effect is reached by mixing a very large number of small particles with fewer large particles and the difference in size between the two types of particles also plays a crucial role. The discovery will help to conceive improved device layouts with more reliable heat dissipation or conservation properties in the future… […]