Search results for "Magnetism"
showing 10 items of 1934 documents
Crystal structure and mössbauer spectroscopy studies of the ferrimagnetic complex bimetallic salt hexaamminechromium (III) hexachloroferrate (III), […
1992
The crystal and molecular structures of the ferrimagnetic bimetallic complex salt hexaamminechromium(III) hexachloroferrate(III), [Cr(NH3)6][FeCl6], have been determined from single-crystal, three-dimensional x-ray diffraction counter data. The compound crystallizes as orange coloured crystals in the space groupC2/c of the monoclinic system with Z=4 and has cell dimensionsa=11.325(1) A,b=11.387(1) A,c=11.233(1) A, and β=90.83(1)A. The structure was refined by using segmented block diagonal least-squares techniques to discrepancy indices R and Rw of 0.0233 and 0.0285, respectively. The metal ions occupy sites with symmetry $$\bar 1$$ and are nearly octahedrally coordinated. In the [FeCl6]3− …
Towards multifunctional magnetic systems through molecular-programmed self assembly of Re(IV) metalloligands
2015
Abstract The molecular-programmed approach based on the use as ligands of tailor-made metalloligands containing stable six-coordinate rhenium(IV) as paramagnetic centres is presented in this review article. A relatively large amount of spin density is covalent-delocalized away from the rhenium to the peripheral atoms of the ligands in the case of the Re(IV) metalloligands, as shown by polarized neutron diffraction experiments and density functional theory calculations. This feature accounts for the significant through space-magnetic interactions that occur in most of its mononuclear species and more interestingly it also explains the strengthening of the magnetic interactions in the heterom…
Superparamagnetic iron oxide/oleic acid nanoparticles with immobilized organosilicon derivatives ofN-(2-hydroxyethyl)tetrahydroisoquinoline: synthesi…
2013
Superparamagnetic iron oxide/oleic acid nanoparticles bearing lipid-like organosilicon N-(2-hydroxyethyl)-1,2,3,4-tetrahydroisoquinoline derivatives have been synthesized with the aim of their potential biomedical application. X-ray diffraction analysis, Dynamic light-scattering measurements, method of magnetogranulometry and some others have been employed to investigate the morphology and properties of the nanoparticles synthesized. The magnetic core diameter of mixed covered nanoparticles ranged between 4.8 and 9.6 nm. The magnetization analyses showed that the particles are superparamagnetic at room temperature. In vitro cell cytotoxicity and intracellular NO generation caused by the wat…
Single-crystal EPR study of the bimetallic ferrimagnetic chain MnCu(EDTA)·6H2O
1993
Abstract A single-crystal EPR study of the bimetallic chain compound MnCu(EDTA)·6H2O is reported. The angular dependence of the linewidth is discussed in relation to the magnetic dipole-dipole interaction, manganese zerofield splitting (ZFS) and copper hyperfine coupling. The calculation of the second moments indicates that ZFS is comparable to the dipolar contribution. The EPR data support the one-dimensional character of the compound.
Forward doubly-virtual Compton scattering off the nucleon in chiral perturbation theory: II. Spin polarizabilities and moments of polarized structure…
2020
We examine the polarized doubly-virtual Compton scattering (VVCS) off the nucleon using chiral perturbation theory ($\chi$PT). The polarized VVCS contains a wealth of information on the spin structure of the nucleon which is relevant to the calculation of the two-photon-exchange effects in atomic spectroscopy and electron scattering. We report on a complete next-to-leading-order (NLO) calculation of the polarized VVCS amplitudes $S_1(\nu, Q^2)$ and $S_2(\nu, Q^2)$, and the corresponding polarized spin structure functions $g_1(x, Q^2)$ and $g_2(x,Q^2)$. Our results for the moments of polarized structure functions, partially related to different spin polarizabilities, are compared to other th…
Comparative study of the performance of spherical and angular silica and alumina supports in the 1-10-μm size range
1978
Summary Columns packed with four different sets of well characterized packings, spherical silica, angular silica, spherical alumina and angular alumina, varying in mean particle diameter ( d p ) between 1 and 10 μm, were compared. On these columns, the chromatographic permeability ( K 10 ), the column resistance parameter (Φ) and the reduced plate height-velocity dependences were determined under identical and comparable conditions. Discrepancies were found for K 10 and Φ depending on the type of packing and the particle shape. The courses of the h versus v plot, however, were nearly identical for packings with d p > 4 μm, showing a minimum at v ≅ 5 and h = 1.5–2.5 for solutes of k ′ ≅ 0.2 …
Thermomagnetic Properties Improved by Self-Organized Flower-Like Phase Separation of Ferromagnetic Co2Dy0.5Mn0.5Sn
2012
A thermodynamically stable phase separation of Co2Dy0.5Mn0.5Sn into the Heusler compound Co2MnSn and Co8Dy3Sn4 is induced by rapid cooling from the liquid phase. The phase separation forms an ordered flower-like structure on the microscale. The increased scattering of phonons at the phase boundaries reduces the thermal conductivity and thus improves thermoelectric and spincaloric properties.
Factors affecting the moisture permeability of lipid-based edible films: a review.
2002
Moisture transfers inside food products could be controlled or limited by the use of edible films. These are usually based on hydrophobic substances such as lipids to improve barrier efficiency. Water permeability of films is affected by many factors, depending on both the nature of barrier components, the film structure (homogeneous, emulsion, multilayer, etc.), crystal type, shape, size and distribution of lipids, and thermodynamics such as temperature, vapor pressure, or the physical state of water in contact to the films. After a brief presentation of lipids and hydrophobic substances used as moisture barrier, cited in the scientific literature, this article reviews all of the parameter…
Influence of sodium lauryl sulphate on the in vitro percutaneous absorption of compounds with different lipophilicity
1997
Abstract The effects of sodium lauryl sulphate (SLS) at different concentrations on the “in vitro” percutaneous absorption of a number of compounds (5-fluorouracil, antipyrine, pentoxifylline, salicylamide, 4-ethylaniline, 4-n-butylaniline and indomethacin) with a wide range of lipophilicity values (log POCT from −0.95 to 4.42) through rat skin were analysed. After pretreatment of the skin with SLS (1% and 5%, w/w) the permeability coefficients increased only for compounds having a log POCT
Ferromagnetic coupling and magnetic anisotropy in oxalato-bridged trinuclear chromium(iii)-cobalt(ii) complexes with aromatic diimine ligands
2010
Two novel heterotrinuclear chromium(III)-cobalt(II) complexes of formula {[Cr(III)(bpy)(ox)(2)](2)Co(II)(Me(2)bpy)}.2H(2)O (1) and {[Cr(III)(phen)(ox)(2)](2)Co(II)(Me(2)bpy)}.1.5H(2)O (2) [ox = oxalato, bpy = 2,2'-bipyridine, Me(2)bpy = 6,6'-dimethyl-2,2'-bipyridine, and phen = 1,10-phenanthroline] have been synthesized using the "complex-as-ligand/complex-as-metal" strategy. The X-ray crystal structure of 2 consists of neutral oxalato-bridged Cr(III)(2)Co(II) bent entities formed by the coordination of two anionic [Cr(III)(phen)(ox)(2)](-) complexes through one of their oxalato groups toward a cationic cis-[Co(II)(Me(2)bpy)](2+) complex. The three tris(chelated), six-coordinated metal atom…