73 research outputs found
Prediction of thermal radiative properties (300–1000 K) of La2NiO4+δ ceramics.
A multiscale numerical model is developed to predict the thermal radiative properties (TRP) of rough La2NiO4+δ coatings. The model integrates intrinsic and extrinsic contributions related to the chemical composition and the texture, respectively. High-temperature infrared reflectivity and thermogravimetric measurements on a La2NiO4+δ single crystal make it possible to understand the role of the excess oxygen in the intrinsic TRP. We show that dense ceramics with thicknesses higher than 4 μm are optically thick, and that one can adjust the surface roughness parameters to predict their TRP
Persistent M2 phase in strongly strained (011)-oriented grains in VO2 films grown on sapphire (001) in reactive sputtering
This work was supported by a Grant-in-Aid for Scientific Research (Grant No. 15K04652) from the Japan Society for the Promotion of Science.We report on the first observation of the persistent M2 phase in strongly strained (011)-oriented grains in VO₂ films grown on Al₂O₃ (001) substrates by means of conventional rf reactive sputtering under adequate deposition conditions. Spatially resolved micro-Raman spectra clearly showed that (011)-oriented large crystalline grains with the cR-axis parallel to the substrate resulted in the appearance of the M2 phase over a wide temperature range of 30 °C. A close correlation of the appearance range of the M2 phase with the in-plane tensile stress of (011)-oriented grains was revealed by X-ray diffraction. We present a phase diagram for the M1, M2, and R phases in relation to the stress of (011)-oriented grains and temperature. It was shown that (011)-oriented micrometer-sized long grains play a crucial role in the emerging structural phase transition (SPT) via an M2 phase even in a film grown on Al₂O₃ (001), which is ordinarily reserved for the (020)-oriented VO₂ growth. The results shown here will contribute to make clear the conditions for obtaining VO₂ films with the appearance of the M2 phase in their SPT process
Nitrogen and group-IV (Si, Ge) vacancy color centres in nano-diamonds: photoluminescence study at high temperature (25 °C–600 °C)
International audienc
Oriented and polycrystalline NdNiO3 thin films on silicon substrate
International audienc
Electronic conduction and microstructure in polymer composites filled with carbonaceous particles.
International audienc
Electron diffraction and Raman scattering evidence of a symmetry breaking at the metal-insulator transition of NdNiO 3
International audienc
New Adsorbent Material Based on Nitrothiophene-Functionalized Silica Particles for Aqueous Heavy Metals Removal
International audience[No abstract
X-ray diffraction investigation of the relationship between strains and metal-insulator transition in NdNiO3 thin films
International audienc
Electron doped (Sm1−x,Cax)MnO3 perovskite manganite as potential infrared thermochromic switch
International audienc
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