Thickness-dependent thermal properties of amorphous insulating thin films measured by photoreflectance microscopy

In this work, we report on the measurement of the thermal conductivity of thin insulating films of SiO2 obtained by thermal oxidation, and Al2O3 grown by atomic layer deposition (ALD), both on Si wafers. We used photoreflectance microscopy to determine the thermal properties of the films as a function of thickness in the 2 nm to 1000 nm range. The effective thermal conductivity of the Al2O3 layer is shown to decrease with thickness down to 70% for the thinnest layers. The data were analyzed upon considering that the change in the effective thermal conductivity corresponds to an intrinsic thermal conductivity associated to an additional interfacial thermal resistance. The intrinsic conductivity and interfacial thermal resistance of SiO2 were found to be equal to 0.95 W/m·K and 5.1 × 10− 9 m2K/W respectively; those of Al2O3 were found to be 1.56 W/m·K and 4.3 × 10− 9 m2K/W

Understanding landscape multifunctionality in a post-forest frontier:Supply and demand of ecosystem services in eastern Amazonia

Sustainable food production requires approaches that reconcile agricultural production with the conservation and sustainable use of natural resources, biodiversity and associated ecosystem services. While the contribution of agriculture to the provision of individual ecosystem services has received considerable scientific attention, little is known about the extent to which tropical landscapes can meet societal expectations related to food production and environmental sustainability simultaneously. We assessed how the spatial configuration of pedo-morphology and land uses influences the provision of three soil-based ecosystem services in eastern Amazonia: carbon storage (CS), habitat for biodiversity (HB), and agricultural commodity production (CP). We use the Functional Land Management framework to assess the supply and demand of these ecosystem services in a spatially explicit manner to identify areas of (mis)matches and trade-offs in the municipality of Paragominas, Brazil. The supply of ecosystem services was informed by a literature review for the various combinations of pedo-morphological characteristics and land uses in the region. The demand for ecosystem services was mapped based on federal and state policy targets. Mapping the supply and demand of CS indicated that half of the carbon in the region is stored in remnants of undisturbed forest which cover only a third of the municipality. Demand for HB in terms of forested area is met but it does not guarantee safeguarding biodiversity. Roughly a third of the territory shows scarce quality of HB even when compliant with legislation. Concerning CP, we identified areas where both supply and the demand to increase production are relative high due to road access and lower intensification costs. The demand for agricultural production can eventually incentivize the expansion of agriculture on fertile soils, which could compromise environmental targets. Our results suggest that the simultaneous delivery of multiple ecosystem services may require land-use pathways that combine land sparing and sharing approaches. Our analysis can inform integrated land-use planning initiatives where, historically, the supply and demand for CP have been the single dominant driver for the current landscape configuration.</p

Nanoscale Thermophysical Metrology and Scanning Thermal Microscopy

International audienc

Scanning thermal microscopy: heat transfer through water meniscus at nanoscale contacts

International audienc

Benefits of ALD for probing dimensionally confined heat transfer

International audienc

Thermal conductivity of Si 2D phononic membranes studied by MD simulations and Raman thermometry

International audienc

Effective thermal conductivity of nanophononic membrane strips investigated by scanning thermal microscopy and Raman thermometry

International audienc