Publications associées à Métal réfractaire

Enhanced radio-frequency performance of niobium films on copper substrates deposited by high power impulse magnetron sputtering

We present a study of radio frequency properties of niobium films deposited on copper by two different approaches based on High Power Impulse Magnetron Sputtering, namely with a DC voltage biased substrate and with bipolar target voltage. Such approaches e ...

2022

Liquid metal infiltration of silicon based alloys into porous carbonaceous materials. Part I: Modelling of channel filling and reaction phase formation

Ludger Weber, Alberto Ortona, Manoj Kondibhau Naikade

A relation for an adequate pore fraction needed to obtain residual Si and C free composites via reactive Si-X alloy infiltration is presented. The volume ratio of SiC and carbonaceous phase, the composition of the infiltrating liquid and the apparent densi ...

ELSEVIER SCI LTD2022

A concept for the extraction of the most refractory elements at CERN-ISOLDE as carbonyl complex ions

João Pedro Fernandes Pinto Ramos

We introduce a novel thick-target concept tailored to the extraction of refractory 4d and 5d transition metal radionuclides of molybdenum, technetium, ruthenium and tungsten for radioactive ion beam production. Despite the more than 60-year old history of ...

2022

Systematic investigations of uranium carbide composites oxidation from micro- to nano-scale: Application to waste disposal

Nhât-Tân Vuong

The production of radioisotope beams at the ISOLDE (Isotope Separator OnLine DEvice) facility at CERN is achieved by irradiating target materials (e.g. uranium carbides and metal foils) with protons. The materials are usually operated at temperatures above ...

EPFL2021

Nanoscale Mass-Spectrometry Imaging of Grain Boundaries in Perovskite Semiconductors

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Hiroyuki Kanda, Paul Gratia, Tom Theodorus Antonius Lummen

Incorporation of alkali metals such as Cs+, Rb+, and K+ into hybrid organic-inorganic halide lead perovskites (HOIPs) generally improves the optoelectronic properties of HOIPs. However, it is still uncertain how alkali metals interact and distribute within ...

2020

Activation of small molecules promoted by multimetallic complexes supported by redox active ligands

Davide Toniolo

The activation of small molecule is a topic of high current interest. A variety of homogeneous end heterogeneous catalysts have been studied to be able to promote chemical transformation of industrial relevance under mild condition and therefore decrease t ...

EPFL2020

Slowing the Kinetics of Alumina Sol-Gel Chemistry for Controlled Catalyst Overcoating and Improved Catalyst Stability and Selectivity

Jeremy Luterbacher, Yuan-Peng Du, Florent Emmanuel Héroguel

Catalyst overcoating is an emerging approach to engineer surface functionalities on supported metal catalyst and improve catalyst selectivity and durability. Alumina deposition on high surface area material by sol–gel chemistry is traditionally difficult t ...

2018

Evidence from Tm anomalies for non-CI refractory lithophile element proportions in terrestrial planets and achondrites

Philippe Gillet

Thulium is a heavy rare earth element (REE) whose geochemical behavior is intermediate between Er and Yb, and that is not expected to be decoupled from these elements during accretion of planetary bodies and geological processes. However, irregularities in ...

Pergamon-Elsevier Science Ltd2016

Titanium oxide aerogel composites

László Forró, Arnaud Magrez, Endre Horvath

The invention relates to titanium oxide aerogels, in particular to titanium oxide binary or ternary (e.g. titanium oxide-carbon) aerogel monoliths possessing ordered meso- and macroporosity. The porous scaffold can be made with or without addition of binde ...

2016

Flame-Made WO3/CeOx-TiO2 Catalysts for Selective Catalytic Reduction of NOx by NH3

Davide Ferri

Materials based on a combination of cerium-tungsten-titanium are potentially durable catalysts for selective catalytic NOx reduction using NH3 (NH3-SCR). Flame-spray synthesis is used here to produce WO3/CeOx-TiO2 nanoparticles, which are characterized wit ...

American Chemical Society2015