Conţinutul numărului revistei |
Articolul precedent |
Articolul urmator |
279 0 |
SM ISO690:2012 KORCHAGIN, Denis, PALII, Andrew, YURIEVA, Elena, AKIMOV, Alexander, MISOCHKO, Eugenii, SHILOV, Gennadii, TALANTSEV , Artem, MORGUNOV, Roman, SHAKIN, Alexander, ALDOSHIN, Serghei, TSUKERBLAT, Boris S.. Evidence of field induced slow magnetic relaxation in: Cis -[Co(hfac)2(H2O)2] exhibiting tri-axial anisotropy with a negative axial component. In: Dalton Transactions, 2017, nr. 23(46), pp. 7540-7548. ISSN 1477-9226. DOI: https://doi.org/10.1039/c7dt01236e |
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Dalton Transactions | |
Numărul 23(46) / 2017 / ISSN 1477-9226 /ISSNe 1477-9234 | |
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DOI:https://doi.org/10.1039/c7dt01236e | |
Pag. 7540-7548 | |
Rezumat | |
We report a combined experimental characterization and theoretical modeling of the hexa-coordinated high-spin Co(ii) complex cis-[Co(hfac)2(H2O)2] (I). The magnetic static field (DC) data and EPR spectra (measurements were carried out on the powder samples of diluted samples cis-[Co0.02Zn0.98 (hfac)2(H2O)2]) were analyzed with the aid of the parametric Griffith Hamiltonian for the high-spin Co(ii) supported by the ab initio calculations of the crystal field (CF) parameters, g-factors and superexchange parameters between H-bonded Co(ii) ions in the neighboring molecules in a 1D network. This analysis suggests the presence of the easy axis of magnetic anisotropy and also shows the existence of a significant rhombic component. The detected frequency dependent (AC) susceptibility signal shows that complex I exhibits slow paramagnetic relaxation in the applied DC field belonging thus to the class of non-uniaxial field induced single ion magnets with a negative axial component of anisotropy. It is demonstrated that the main contributions to the relaxation come from the direct one-phonon process dominating at low temperatures, while the contribution of the two-phonon Raman process becomes important with increasing temperature. |
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Cuvinte-cheie Anisotropy, Calculations, cobalt, Cobalt compounds, Complex networks, Coordination reactions, Electron spin resonance spectroscopy, Hamiltonians, magnetism, phonons |
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