Search results for "SOS"
showing 10 items of 8138 documents
Impact of Annealing Temperature on Tunneling Magnetoresistance Multilayer Stacks
2020
The effect of annealing temperatures on the tunnel magnetoresistance (TMR) of MgO-based magnetic tunnel junctions (MTJs) has been investigated for annealing between 190 and 370°C. The TMR shows a maximum value of 215% at an annealing temperature of 330°C. A strong sensitivity of the TMR and the exchange bias of the pinned ferromagnetic layers on the annealing temperature are observed. Depending on sensor application requirements, the MTJ can be optimized either for stability and pinning strength or for a high TMR signal by choosing the appropriate annealing temperature. The switching mechanism of the ferromagnetic layers in the MTJ and the influence of the annealing on the layer properties,…
Influence of surface topography on depth profiles obtained by Rutherford backscattering spectrometry
2000
A method for determining correct depth profiles from samples with rough surfaces is presented. The method combines Rutherford backscattering spectrometry with atomic force microscopy. The topographical information obtained by atomic force microscopy is used to calculate the effect of the surface roughness on the backscattering spectrum. As an example, annealed Au/ZnSe heterostructures are studied. Gold grains were observed on the surfaces of the annealed samples. The annealing also caused diffusion of gold into the ZnSe. Backscattering spectra of the samples were measured with a 2 MeV 4He+ ion beam. A scanning nuclear microprobe was used to verify the results by measuring backscattering fro…
High-frequency EPR study on Cu4Cu- and Co4Co-metallacrown complexes
2019
Abstract High-frequency/high-field electron paramagnetic resonance studies on two homonuclear 12-MC-4 metallacrown complexes Cu4Cu and Co4Co are presented. For Cu4Cu, our data imply axial-type g-anisotropy with g x = 2.03 ± 0.01 , g y = 2.04 ± 0.01 , and g z = 2.23 ± 0.01 , yielding g = 2.10 ± 0.02 . No significant zero field splitting (ZFS) of the ground state mode is observed. In Co4Co, we find a m S = ± 3 / 2 ground state with g = 2.66 . The data suggest large anisotropy D of negative sign.
Magnetic properties of exciton trapped by an off-center ionized donor in single quantum dot
2021
Abstract It is known that the lines of exciton (X) and exciton trapped by an ionized donor ( D + , X ) are often very close which makes very difficult their experimental identification. In order to facilitate their distinction in spherical quantum dots, we investigate the effect of an applied magnetic field studying the binding energy of the complex ( D + , X ) as function of dot size and the ionized donor position. Our calculation is using a variational approach taking into account the interactions between all charge carriers. Our results show that the complex is more sensitive to the magnetic field than the exciton and that the energy of the exciton is not sufficiently affected when the i…
Multiscale model approach for magnetization dynamics simulations
2016
Simulations of magnetization dynamics in a multiscale environment enable the rapid evaluation of the Landau-Lifshitz-Gilbert equation in a mesoscopic sample with nanoscopic accuracy in areas where such accuracy is required. We have developed a multiscale magnetization dynamics simulation approach that can be applied to large systems with spin structures that vary locally on small length scales. To implement this, the conventional micromagnetic simulation framework has been expanded to include a multiscale solving routine. The software selectively simulates different regions of a ferromagnetic sample according to the spin structures located within in order to employ a suitable discretization…
Topological two-dimensional Su–Schrieffer–Heeger analog acoustic networks: Total reflection at corners and corner induced modes
2021
In this work, we investigate some aspects of an acoustic analogue of the two-dimensional Su-Schrieffer-Heeger model. The system is composed of alternating cross-section tubes connected in a square network, which in the limit of narrow tubes is described by a discrete model coinciding with the two-dimensional Su-Schrieffer-Heeger model. This model is known to host topological edge waves, and we develop a scattering theory to analyze how these waves scatter on edge structure changes. We show that these edge waves undergo a perfect reflection when scattering on a corner, incidentally leading to a new way of constructing corner modes. It is shown that reflection is high for a broad class of edg…
Interface evolution during magnetic pulse welding under extremely high strain rate collision: mechanisms, thermomechanical kinetics and consequences
2020
Abstract Magnetic pulse welding enables to produce perplexing interfacial morphologies due to the complex material response during the high strain rate collision. Thus, a thermomechanical model is used in this study to investigate the formation mechanism of the wake, vortex, swirling and mesoscale cavities with the increase of the impact intensity at the interface. The formation of these interfacial features are difficult to characterize by insitu methods, thus the origin of phenomena still remain a subject of open discussion. Our studies identify the governing mechanisms and the associated thermomechanical kinetics, which are responsible for the formation mechanism of interfacial features.…
Color centers in diamond as novel probes of superconductivity
2018
Magnetic imaging using color centers in diamond through both scanning and wide-field methods offers a combination of unique capabilities for studying superconductivity, for example, enabling accurate vector magnetometry at high temperature or high pressure, with spatial resolution down to the nanometer scale. The paper briefly reviews various experimental modalities in this rapidly developing nascent field and provides an outlook towards possible future directions.
Spin crossover (SCO) iron(II) coordination polymer chain: Synthesis, structural and magnetic characterizations of [Fe(abpt)2(μ-M(CN)4)] (M=PtII and N…
2013
Abstract New iron(II) coordination polymeric neutral chain of formula [Fe(abpt) 2 (μ-M(CN) 4 )], with M = Pt II ( 1 ), Ni II ( 2 ) and abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole, have been synthesized and characterized by infrared spectroscopy, X-ray diffraction and magnetic measurements. The two compounds are isostructural as deduced from a Rietveld analysis of X-ray powder diffraction data of 2 simulated from the single crystal structure of 1 . The crystal packing of 1 is formed by regular chains running along the crystallographic [−1 0 1] direction where the planar [Pt(CN) 4 ] 2− anion acts as a μ 2 -bridging ligand via two nitrogen atoms of two different trans cyano groups, whi…
Identification and H(D)-bond energies of C-H(D)Cl interactions in chloride-haloalkane clusters: a combined X-ray crystallographic, spectroscopic, and…
2016
The cationic (1,3,5-triazapentadiene)Pt(II) complex [Pt{NH[double bond, length as m-dash]C(N(CH2)5)N(Ph)C(NH2)[double bond, length as m-dash]NPh}2]Cl2 ([]Cl2) was crystallized from four haloalkane solvents giving [][Cl2(CDCl3)4], [][Cl2(CHBr3)4], [][Cl2(CH2Cl2)2], and [][Cl2(C2H4Cl2)2] solvates that were studied by X-ray diffraction. In the crystal structures of [][Cl2(CDCl3)4] and [][Cl2(CHBr3)4], the Cl(-) ion interacts with two haloform molecules via C-DCl(-) and C-HCl(-) contacts, thus forming the negatively charged isostructural clusters [Cl(CDCl3)2](-) and [Cl(CHBr3)2](-). In the structures of [][Cl2(CH2Cl2)2] and [][Cl2(C2H4Cl2)2], cations [](2+) are linked to a 3D-network by a syste…