Search results for "MATTER"
showing 10 items of 16762 documents
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…
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
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.
Structural and morphological characterization of the Cd-rich region in Cd1-xZnxO thin films grown by atmospheric pressure metal organic chemical vapo…
2019
Abstract We have analysed the growth, morphological and structural characterization of Cd1-xZnxO thin films grown on r-sapphire substrates by atmospheric pressure metal organic chemical vapour deposition, mainly focusing on the Cd-rich rock-salt phase for its promising optical and technological applications. The evolution of the surface morphology and crystalline properties as a function of Zn content has been studied by means of high resolution x-ray diffraction and electron microscopy techniques. Monocrystalline (002) single-phase cubic films were obtained with Zn contents up to 10.4%, and with a low density of dislocations as a consequence of the optimized crystal growth process. Particu…
MOCVD growth of CdO very thin films: Problems and ways of solution
2016
Abstract In this paper the growth of CdO by the MOCVD technique at atmospheric pressure has been studied in order to achieve very thin films of this material on r-sapphire substrates. The growth evolution of these films was discussed and the existence of a threshold thickness, below which island-shaped structures appear, was demonstrated. Some alternatives to reduce this threshold thickness have been proposed in the frame of the analysis of the crystal growth process. The morphology and structural properties of the films were analyzed by means of SEM and HRXRD. High-quality flat CdO samples were achieved with thicknesses up to 20 nm, which is five times thinner than the values previously re…
The challenge in realizing an exchange coupled BiFeO3-double perovskite bilayer
2020
Abstract In this work we propose a device design for efficient voltage control of magnetism. The magnetization of a ferrimagnetic double perovskite may be manipulated by an exchange coupled layer of multiferroic BiFeO3. Bilayers of Barium doped BiFeO3 and ferrimagnetic double perovskite Sr2FeMoO6 have been prepared by pulsed laser deposition motivated by the possibility of strong interlayer exchange coupling. While single layers of each material show high quality we observe that in both stacking orders the first layer decomposes during the deposition of the second layer. The reason for the decomposition are strongly differing growth conditions for BiFeO3 and Sr2FeMoO6. This means that the g…
New low-temperature phosphate glasses as a host for Europium Ions
2021
Abstract Artificial lightining, especially that of light emitting diodes, and telecommunications are penetrating every part of human lives daily. Different compositions phosphate glasses were suggested as a suitable host material for Eu3+ ions. Here rare earth metal ions act as luminescent centers also perturbing the bond order of phosphate glass network comprised of (PO4)3−, [−(O)PO3]2−, [−(O)2PO2]−, [−(O)3PO] structural units, which is indicated by Raman spectroscopy, confirming successful integration of aforementioned ions into the glass material. Glasses doped with Eu3+ ions show their typical photoluminescence spectra in low symmetry environment, consisting of the highest intensity 5D0…
A multilayer model for self-propagating high-temperature synthesis of inter-metallic compounds
2007
International audience; Self-propagating high-temperature synthesis of intermetallic compounds is of wide interest. We consider reactions in a binary system in which the rise and fall of the temperature during the reaction is such that one of the reacting metals melts but not the other. For such a system, using the phase diagram of the binary system, we present a general theory that describes the reaction taking place in a single solid particle of one component surrounded by the melt of the second component. The theory gives us a set of kinetic equations that describe the propagation of the phase interfaces in the solid particle and the change in composition of the melt that surrounds it. I…
Theoretical insights on the importance of anchoring vs molecular geometry in magnetic molecules acting as junctions
2019
The anchoring of the molecule to an electrode is known to be a key factor in single-molecule spintronics experiments. Likewise, a relaxation down to the most stable geometry is a critical step in theoretical simulations of transport through single-molecule junctions. Herein we present a set of calculations designed to analyze and compare the effect of different anchoring points and the effect of perturbations in the molecular geometry and interelectrode distance. As model system we chose the [V($\alpha$-C$_3$S$_5$)$_3$]$^{2-}$ complex connecting two Au(111) electrodes in a slightly compressed geometry. In our calculations, the attachment happens through an S-Au bond, a common anchoring stra…
Synthesis of ZnO–Ag2CO3–Fe3O4@rGO core–shell structure: magnetically separable photocatalyst for degradation of MB using the Box–Behnken design
2020
In this work, a simple microwave method was utilized to prepare ZnO sheet linked with Fe3O4@rGO core–shell and of Ag2CO3 through formation of the quadri-photocatalytic with high activity. The microstructure, morphology, spectroscopic, and magnetic characteristics of the prepared samples were assessed using XRD, SEM, PL, TEM, FT-IR, DLS, and VSM analysis. The photocatalytic activity of the material was evaluated for photodegradation of methylene blue dye under the UV and visible light with home-made photoreactor. The response surface method in a Box–Behnken design was utilized to design the experiments. The parameters affecting the efficiency of the degradation including, pH (5–9), photocata…