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Paramagnetic Resonance Spectra (paramagnetic + resonance_spectrum)

Distribution by Scientific Domains
Physics and Astronomy40%

Kinds of Paramagnetic Resonance Spectra

  • electron paramagnetic resonance spectrum
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    Selected Abstracts

    Theoretical study of electron paramagnetic resonance spectra and local structure of trigonal [Cr(H2O)6]3+ complex in GASH:Cr3+ and AlCl3,·,6H2O:Cr3+ systems at different temperatures

    PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2010
    Yan-Fang Li
    Abstract The electron paramagnetic resonance (EPR) parameters and local structure of the octahedral [Cr(H2O)6]3+ complex for Cr3+ doped in GASH and AlCl3,·,6H2O crystals with trigonal symmetry have been studied on the basis of the 120,×,120 complete energy matrices, respectively. By simulating the EPR and optical spectra, the local structure distortion parameters are determined in the temperature range of 4.2,297,K. The calculated results show that the local structure of [Cr(H2O)6]3+ octahedron exhibits an elongated distortion and the value of distortion depends on the temperature. Furthermore, the interrelation between the g -factors and orbit-reduction factor k has been studied, and the influence of the local structure on the EPR parameters has also been discussed. [source]

    Investigation of ferroelectric nanopowders by EPR method

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2007
    A. M. Slipenyuk
    Abstract BaTiO3 nanopowders with different particle sizes have been studied by Electron Paramagnetic Resonance method over a temperature range covering the ferroelectric-paraelectric transition. Iron and manganese impurities were used as probes for these experiments. The evolution of the spectra over the transition was observed through 1) the change in symmetry of Fe3+ from tetragonal to cubic and 2) the appearance beyond TC of Mn2+ characteristic lines. The results were analyzed according to a theoretical model proposed by one of the authors to extract the distribution of the particles size from the electron paramagnetic resonance spectra. Both the mean particle radius R0 and the dispersion , showed a very good agreement with the data obtained from direct measurement of the size distribution. This evidences both the critical influence of the nanoparticles sizes distribution on the EPR spectra's main features and on the temperature dependence of the polarization. In the framework of the theoretical model proposed by one of the authors the distribution of the particles size was extracted from the electron paramagnetic resonance spectra. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Copper(II) succinate complexes with 1,2-di-4-pyridylethane and 1,3-di-4-pyridylpropane

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2009
    M. J. González Garmendia
    The compounds poly[di-,4 -succinato-,2 -1,2-di-4-pyridylethane-dicopper(II)], [Cu2(C4H4O4)2(C12H12N2)]n, (I), and poly[di-,4 -succinato-,2 -1,3-di-4-pyridylpropane-dicopper(II)], [Cu2(C4H4O4)2(C13H14N2)]n, (II), exhibit polymeric structures with the dicopper units doubly bridged by bis-bidentate succinate groups and crosslinked by the separator bis(pyridyl) molecules. In (I), the molecule exhibits a centre of inversion located midway between the core Cu-dimer atoms and another that relates half of the bis(pyridyl)ethane ligand to the other half. Compound (II) has a similar molecular packing but with a doubled lattice constant and noncentrosymmetric core units. An antiferromagnetic interaction due to the dinuclear copper units was deduced from magnetic subsceptibility measurements, and spin triplet signals were detected in the electron paramagnetic resonance spectra for both compounds. [source]

    EPR OF Mn2+ IMPURITIES IN CALCITE: A DETAILED STUDY PERTINENT TO MARBLE PROVENANCE DETERMINATION,

    ARCHAEOMETRY, Issue 1 2009
    H. WEIHE
    We demonstrate that the electron paramagnetic resonance spectrum of Mn2+ impurities in calcite, and therefore also in marble, may be accurately reproduced by a traditional spin Hamiltonian formalism. The success of such a treatment, however, very much depends on the spin Hamiltonian parameters having the correct signs as well as magnitudes. We present data that determine the sign of the axial anisotropy parameter and thereby facilitate future quantum mechanical characterizations of marble electron paramagnetic resonance spectra that supplement provenance determination. [source]