Search results for "Material"
showing 10 items of 32550 documents
Ab Initio Modeling of Y and O Solute Atom Interaction in Small Clusters within the bcc Iron Lattice
2018
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euroatom research and training programme 2014–2018 under grant agreement No 633053. The authors are indebted to A. Möslang and P. V. Vladimirov for stimulating discussions. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
2018
CrN thin films with an N/Cr ratio of 95% were deposited by reactive magnetron sputtering onto (0 0 0 1) sapphire substrates. X-ray diffraction and pole figure texture analysis show CrN (1 1 1) epitaxial growth in a twin domain fashion. By changing the nitrogen versus argon gas flow mixture and the deposition temperature, thin films with different surface morphologies ranging from grainy rough textures to flat and smooth films were prepared. These parameters can also affect the CrN x system, with the film compound changing between semiconducting CrN and metallic Cr2N through the regulation of the nitrogen content of the gas flow and the deposition temperature at a constant deposition pressur…
The α and γ plasma modes in plasma-enhanced atomic layer deposition with O2-N2 capacitive discharges
2017
Two distinguishable plasma modes in the O2–N2 radio frequency capacitively coupled plasma (CCP) used in remote plasma-enhanced atomic layer deposition (PEALD) were observed. Optical emission spectroscopy and spectra interpretation with rate coefficient analysis of the relevant processes were used to connect the detected modes to the α and γ modes of the CCP discharge. To investigate the effect of the plasma modes on the PEALD film growth, ZnO and TiO2 films were deposited using both modes and compared to the films deposited using direct plasma. The growth rate, thickness uniformity, elemental composition, and crystallinity of the films were found to correlate with the deposition mode. In re…
Tuning of interfacial perpendicular magnetic anisotropy and domain structures in magnetic thin film multilayers
2019
We investigate the magnetic domain structures and the perpendicular magnetic anisotropy (PMA) arising in CoFeB films interfaced with selected heavy metal (HM) layers with large spin Hall angles in HM/CoFeB/MgO (HM = W, Pt, Pd, W x Ta1−x ) stacks as a function of CoFeB thickness and composition for both as-deposited and annealed materials stacks. The coercivity and the anisotropy fields of annealed material stacks are higher than for the as-deposited stacks due to crystallisation of the ferromagnetic layer. Generally a critical thickness of MgO > 1 nm provides adequate oxide formation at the top interface as a requirement for the generation of PMA. We demonstrate that in stacks with Pt as th…
Quantitative analysis of magnetization reversal in Ni thin films on unpoled and poled (0 1 1) [PbMg1/3Nb2/3O3]0.68–[PbTiO3]0.32piezoelectric substrat…
2016
The field angle dependence of the magnetization reversal in 20 nm thick polycrystalline Ni films grown on piezoelectric (0 1 1) [PbMg1/3Nb2/3O3](0.68)-[PbTiO3](0.32) (PMN-PT) substrates is analysed quantitatively to study the magnetic anisotropy induced in the film by poling the piezosubstrate. While the PMN-PT is in the unpoled state, the magnetization reversal is almost isotropic as expected from the polycrystalline nature of the film and corresponding to an orientation ratio (OR) of 1.2. The orientation ratio is obtained by fitting the angular dependence of normalized remanent magnetization to an adapted Stoner-Wohlfarth relation. Upon poling the piezosubstrate, a strong uniaxial anisotr…
2020
Recent experiments have demonstrated the formation of free-standing Au monolayers by exposing the Au–Ag alloy to electron beam irradiation. Inspired by this discovery, we used semi-empirical effective medium theory simulations to investigate monolayer formation in 30 different binary metal alloys composed of late d-series metals such as Ni, Cu, Pd, Ag, Pt, and Au. In qualitative agreement with the experiment, we find that the beam energy required to dealloy Ag atoms from the Au–Ag alloy is smaller than the energy required to break the dealloyed Au monolayer. Our simulations suggest that a similar method could also be used to form Au monolayers from the Au–Cu alloy and Pt monolayers from Pt–…
Explosive crystallization in amorphous CuTi thin films: a molecular dynamics study
2019
Abstract Molecular dynamic simulation was used to study mechanism of self-propagating waves of explosive crystallization (devitrification) in the CuTi metallic glass. Processes in thin rectangular samples composed of one to two million atoms were simulated and compared with experimental data. It was shown that the nucleation of primary crystalline clusters occurs homogeneously due to spontaneous fluctuations of atomic structure; the clusters not
A review on LiNixCo1−2xMnxO2 (0.1 ≤ x ≤ 0.33) cathode materials for rechargeable Li-ion batteries
2021
Abstract Electrochemical and physical properties of LiNixCo1−2xMnxO2 (0.1 ≤ x ≤ 0.33) electrode materials prepared by self-combustion were investigated. Pure LiNixCo1−2xMnxO2 (x = 0.1, 0.2, 0.33) materials with single phase and R-3 m layered structure were obtained as confirmed by X-ray diffraction. Energy Dispersive Spectroscopy, Scanning Electron Microscopy are commonly used to determine the chemical composition and the distribution of particle size of the three samples. The electrochemical performances of the samples were measured at different current rates in the 3–4.5 V potential range. The studied materials exhibit good discharge capacity. The magnetic susceptibility measurements and …
ABSOLUTE THERMOELECTRIC POWER OF Pb–Sn ALLOYS
2011
International audience; In this work, absolute thermoelectric power (ATP) of Pb, Sn, Pb-20 wt.% Sn, Pb-40 wt.% Sn, Pb-60 wt.% Sn, Pb-80 wt.% Sn are measured. Measurements are performed in a temperature gradient furnace from 20 degrees C to 500 degrees C, for both solid and liquid states. Temperatures are measured with T-type copper-constantan thermocouples, while voltage signal between copper electrodes of those thermocouples is recorded in order to calculate ATP of the sample metal.
The effects of thermal treatment on structural, morphological and optical properties of electrochemically deposited Bi2S3 thin films
2017
Abstract Thin films of bismuth sulfide (Bi 2 S 3 ) have been electrochemically deposited on indium–doped tin oxide substrates from aqueous solutions of Bi(NO 3 ) 3 , ethylene diamine tetraacetic acid (EDTA) and Na 2 S 2 O 3 . The structural properties of the films were characterized using X–ray diffraction and high–resolution transmission electron microscopy analyses. The film crystallizes in an orthorhombic structure of Bi 2 S 3 along with metallic bismuth. Thermal annealing of the prepared film in sulfur atmosphere improves its crystallinity and cohesion. The band gap values of the deposited film before and after annealing at 400 °C were found to be 1.28 and 1.33 eV, respectively.