Search results for "Magnetization"
showing 10 items of 550 documents
Magnetic properties of MoS 2 nanotubes doped with lithium
2003
DC magnetization measurements of lithium-doped molybdenum sulfide nanotubes (LixMoS2, 2.2 10 kOe, the nonlinear part in H<5 kOe with saturation at approximately 10 kOe can be observed. This suggests a formation of ferromagnetic clusters even at room temperature. No magnetic phase transition between 2 and 300 K has been detected.
Variation of the ground spin state in homo- and hetero-octanuclear copper(II) and nickel(II) double-star complexes with a meso-helicate-type metallac…
2011
Homo- and heterometallic octanuclear complexes of formula Na₂{[Cu₂(mpba)₃][Cu(Me₅dien)]₆}-(ClO₄)₆·12H₂O (1), Na₂{[Cu₂(Mempba)₃][Cu(Me₅dien)]₆}(ClO₄)₆·12H₂O (2), Na₂{[Ni₂(mpba)₃]-[Cu(Me₅dien)]₆}(ClO₄)₆·12H₂O (3), Na₂{[Ni₂(Mempba)₃][Cu(Me₅dien)]₆}(ClO₄)₆·9H₂O (4), {[Ni₂(mpba)₃][Ni(dipn)(H₂O)]₆}(ClO₄)₄·12.5H₂O (5), and {[Ni₂(Mempba)₃][Ni(dipn)-(H₂O)]₆}(ClO₄)₄·12H₂O (6) [mpba = 1,3-phenylenebis(oxamate), Mempba = 4-methyl-1,3-phenylenebis(oxamate), Me₅dien = N,N,N',N'',N''-pentamethyldiethylenetriamine, and dipn = dipropylenetriamine] have been synthesized through the "complex-as-ligand/complex-as-metal" strategy. Single-crystal X-ray diffraction analyses of 1, 3, and 5 show cationic M(II)₂M'(I…
Unusual Magnetic Behavior in the Layered Ferromagnet [Ni(C6H14N2)2]3[Fe(CN)6]2·2H2O
2002
The cyano-bridged molecular complex [Ni(C6H14N2)2]3[Fe(CN)6]2·2H2O, with a rectangular 2D structure, displays long-range ferromagnetic ordering at 14 K, and exhibits unusual magnetic properties for this type of material, as confirmed by the appearance of two different peaks in the AC magnetic susceptibility plot, and a high coercive field (2.3 kOe) and remnant magnetization (6.8 μB). (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)
High-Nuclearity Magnetic Clusters: Generalized Spin Hamiltonian and Its Use for the Calculation of the Energy Levels, Bulk Magnetic Properties, and I…
2001
A general solution of the exchange problem in the high-nuclearity spin clusters (HNSC) containing arbitrary number of exchange-coupled centers and topology is developed. All constituent magnetic centers are supposed to possess well-isolated orbitally non-degenerate ground states so that the isotropic Heisenberg-Dirac-Van Vleck (HDVV) term is the leading part of the exchange spin Hamiltonian. Along with the HDVV term, we consider higher-order isotropic exchange terms (biquadratic exchange), as well as the anisotropic terms (anisotropic and antisymmetric exchange interactions and local single-ion anisotropies). All these terms are expressed as irreducible tensor operators (ITO). This allows u…
A T‐Shaped μ 3 ‐Oxido Trinuclear Iron Cluster with High Easy‐Plane Anisotropy: Structural and Magnetic Characterization
2008
The synthesis, crystal structure and magnetochemical characterization of a new μ-oxido trinuclear iron cluster (oldnomenclature: μ-oxo trinuclear iron cluster), [Fe3(μ3-O)(μ2-CH3O)2(μ2-CH3COO)2(phen)2Cl3], is reported. The reaction of hydrated FeCl3 with sodium acetate and 1,10-phenanthroline in a mixture of methanol and acetonitrile afforded crystals suitable for X-ray crystallographic determination. The new compound crystallizes in the tetragonal I41/a space group (a = b = 13.6322 A, c = 37.3538 A, Z = 8, V = 6941.7 A3). The core of the complex is an isosceles triangle bridged by a μ3-O ion with a rare T-shaped geometry. The chloride ions are bound terminally, and the phenanthroline ligan…
A two-dimensional radical salt based upon BEDT-TTF and the dimeric, magnetic anion [Fe(tdas)2]22−: (BEDT-TTF)2[Fe(tdas)2] (tdas = 1,2,5-thiadiazole-3…
2002
In an attempt to synthesize new synthetic metals which couple magnetic properties to conductivity, we prepared the novel salt (BEDT-TTF)2[Fe(tdas)2] [BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene, hereafter referred to as ET; tdas = 1,2,5-thiadiazole-3,4-dithiolate] by the electrocrystallization technique. The crystal structure of this compound, as determined by single crystal X-ray diffraction, contains conducting, organic ET layers separated by dimerized, magnetic [Fe(tdas)2]22− anions. Due to the magnetic insulating ground electronic state of the ET layer, thermally activated conductivity is observed, with a room temperature value of about 1 S cm−1. This salt was also characterized by…
Charge transport through spin-polarized tunnel junction between two spin-split superconductors
2019
We investigate transport properties of junctions between two spin-split superconductors linked by a spin-polarized tunneling barrier. The spin-splitting fields in the superconductors (S) are induced by adjacent ferromagnetic insulating (FI) layers with arbitrary magnetization. The aim of this study is twofold: On the one hand, we present a theoretical framework based on the quasiclassical Green's functions to calculate the Josephson and quasiparticle current through the junctions in terms of the different parameters characterizing it. Our theory predicts qualitative new results for the tunneling differential conductance, $dI/dV$, when the spin-splitting fields of the two superconductors are…
Anomalous current in diffusive ferromagnetic Josephson junctions
2017
We demonstrate that in diffusive superconductor/ferromagnet/superconductor (S/F/S) junctions a finite, anomalous Josephson current can flow even at zero phase difference between the S electrodes. The conditions for the observation of this effect are noncoplanar magnetization distribution and a broken magnetization inversion symmetry of the superconducting current. The latter symmetry is intrinsic for the widely used quasiclassical approximation and prevented previous works based on this approximation from obtaining the Josephson anomalous current. We show that this symmetry can be removed by introducing spin-dependent boundary conditions for the quasiclassical equations at the superconducti…
Prussian Blue Analogues of Reduced Dimensionality
2012
Abstract: Mixed-valence polycyanides (Prussian Blue analogues) possess a rich palette of properties spanning from room-temperature ferromagnetism to zero thermal expansion, which can be tuned by chemical modifications or the application of external stimuli (temperature, pressure, light irradiation). While molecule-based materials can combine physical and chemical properties associated with molecular-scale building blocks, their successful integration into real devices depends primarily on higher-order properties such as crystal size, shape, morphology, and organization. Herein a study of a new reduced-dimensionality system based on Prussian Blue analogues (PBAs) is presented. The system is …
Incorporation of CrIII into a Keggin Polyoxometalate as a Chemical Strategy to Stabilize a Labile {CrIIIO4} Tetrahedral Conformation and Promote Unat…
2020
Polyoxometalates (POMs) provide rigid and highly symmetric coordination sites and can be used as a strategy for the stabilization of magnetic ions. Herein, we report a new member of the Keggin archetype, the Cr-centered Keggin anion [α-CrW12O40]5– (CrW12), with the unusual tetrahedral coordination of CrIII reported for the first time in POMs conferring unattended magnetic properties. POM chemistry has recently presented excellent examples of single-molecule and single-ion magnets (SMMs and SIMs) as well as molecular spin qubits; however, the majority of POM-based SIMs reported to date contain lanthanoid ions. CrW12, as the first example of a chromium(III) SIM, exhibits slow relaxation of ma…