Search results for "Surfaces"
showing 10 items of 2837 documents
Investigation of La2O3 and/or (Co,Mn)3O4 deposits on Crofer22APU for the SOFC interconnect application
2009
International audience; Chromia forming alloys (stainless steels) are among the best candidates for SOFC interconnects. However, problems of decreasing electronic conductivity during high temperature service and volatility of chromium oxide scales need to be solved. Electronically conductive surface coatings, which also reduce oxide scale growth and chromium volatility, are needed to improve stainless steel interconnects. The goal of this study is to investigate combinations of lanthanum oxide (La2O3) and cobalt manganese oxide ((Co,Mn)3O4) coatings on Crofer22APU stainless steel. Thin film coatings of La2O3 (~200 nm) and Co,Mn (1:1) (~2 mm) were deposited via metal organic chemical vapor d…
Molecular semiconductor-doped insulator (MSDI) heterojunctions: Oligothiophene/bisphtalocyanine (LuPc2) and perylene/bisphthalocyanine as new structu…
2010
Abstract The combination of a sexithiophene and a perylene diimide derivatives, as p-type and n-type materials, respectively, used as sub-layers, to an intrinsic semiconductor, namely the lutetium bisphthalocyanine, allows to obtain a new transducer for gas sensing. These transducers were called molecular semiconductor-doped insulator (MSDI) heterojunctions, were recently designed and reported, but with only phthalocyanines as active materials. p-Type material leads to MSDIs that exhibit a positive response to ozone and a negative response to ammonia, whereas MSDIs prepared from n-type material exhibit a positive response to ammonia and negative response to ozone. The remarkable point is th…
Phosphites as precursors in atomic layer deposition thin film synthesis
2021
We here demonstrate a new route for deposition of phosphorous based materials by atomic layer deposition (ALD) using the phosphites Me3PO3 or Et3PO3 as precursors. These contain phosphorous in the oxidation state (III) and are open for deposition of reduced phases by ALD. We have investigated their applicability for the synthesis of LiPO and AlPO materials and characterized their growth by means of in situ quartz crystal microbalance. Phosphites are good alternatives to the established phosphate-based synthesis routes as they have high vapor pressure and are compatible with water as a coreactant during deposition. The deposited materials have been characterized using XPS, x-ray fluorescence…
Detection of planar defects caused by ion irradiation in Si using molecular dynamics
2007
We have analyzed the evolution of defects caused by self-irradiation of crystalline silicon. A classical molecular dynamics simulation was followed by defect analysis using the Pixel Mapping (PM) method. The PM identified {311} planar defects and long-chain structures of the so-called interstitial chains following low energy (1 keV) ion impact. The areal density obtained from simulation of self-interstitial atoms was about two thirds of that of experiments reported in the literature [Jpn. J. Appl. Phys. 30 (1991) L639], while the atomic configuration on respective planes agreed exactly.
Advanced time-stamped total data acquisition control front-end for MeV ion beam microscopy and proton beam writing
2013
Many ion-matter interactions exhibit [email protected] time dependences such as, fluorophore emission quenching and ion beam induced charge (IBIC). Conventional event-mode MeV ion microbeam data acquisition systems discard the time information. Here we describe a fast time-stamping data acquisition front-end based on the concurrent processing capabilities of a Field Programmable Gate Array (FPGA). The system is intended for MeV ion microscopy and MeV ion beam lithography. The speed of the system (>240,000 events s^-^1 for four analogue to digital converters (ADC)) is limited by the ADC throughput and data handling speed of the host computer.
Solid proton conductors as room-temperature gas sensors
1993
Ammonia-exchanged ceramic samples of beta alumina have been obtained from plasma-dispersed powders. The ionic conductivity is slightly affected by ion exchange, but the surface conductivity for the amonia-exchanged sample drastically changes in the presence of the water and ammonia vapours. The ammonia-doped xerogel of antimonic acid hydrate in the form of a thick film has been tested as a potentiometric ammonia sensor.
Assembly and Speed in Ion-Exchange-Based Modular Phoretic Microswimmers.
2017
We report an experimental study on ion-exchange-based modular microswimmers in low-salt water. Cationic ion-exchange particles and passive cargo particles assemble into self-propelling complexes, showing self-propulsion at speeds of several micrometers per second over extended distances and times. We quantify the assembly and speed of the complexes for different combinations of ion-exchange particles and cargo particles, substrate types, salt types and concentrations, and cell geometries. Irrespective of the experimental boundary conditions, we observe a regular development of the assembly shape with increasing number of cargo. Moreover, the swimming speed increases stepwise upon increasing…
Determining Magnetite/Maghemite Composition and Core–Shell Nanostructure from Magnetization Curve for Iron Oxide Nanoparticles
2018
Iron oxide magnetic nanoparticles produced by chemical synthesis are usually composed of both magnetite and maghemite phases. Information about the phase composition is typically obtained using Mos...
Role of Donor and Acceptor Substituents on the Nonlinear Optical Properties of Gold Nanoclusters
2018
In recent years, a large number of monolayer-protected clusters (MPCs) have been studied by means of single crystal structure characterization. A central aspect of research on MPCs is the correlation of their interesting optical properties with structural features and the formulation of a theoretical framework that allows interpretation of their unique properties. For this, superatom and jellium models have been proven successful. Little attention, however, has been paid to the influence of the protecting ligands. Here, we investigate the effect of changes in [Au25(SR)18-x(SR′)x]−, where SR′ represents a para-substituted thiophenolate derivative (SPh-4-X). We computed the first hyperpolariz…
Magneto-optical characterization of single crystalline Co2FeAl0.4Si0.6thin films on MgO(1 0 0) substrates with Cr and MgO seed layers
2013
We report on the experimental investigation of the influence of a seed layer on the magnetic properties of the full-Heusler alloy Co2FeAl0.4Si0.6 (CFAS). The studied magnetic films are grown epitaxially on MgO (1 0 0) substrates with Cr and/or MgO seed layers. By employing magneto-optical Kerr effect magnetometry we show that magnetic anisotropy can be tuned by choosing the proper seed layer. The results on CFAS show an overall uniaxial anisotropy plus a biaxial contribution which depends on the seed layer. In addition, if grown on MgO, a sharp increase in the coercive field HC at a series of angles symmetric with respect to the easy axis is present. Scanning Kerr-microscope imaging is perf…