Descripción
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A detailed study of the structure-composition-properties correlation is reported for the asprepared (AP) and two oxygenated (oxygenation carried out at ambient pressure and under high pressure) Mo0.3Cu0.7Sr2ErCu2Oy samples. Their crystal structures were characterized by combining the x-ray/neutron powder diffraction (NPD) and electron diffraction techniques. All the samples show tetragonal symmetry, crystallizing in the P4/mmm space group. The influence of oxygenation in the electronic states for the Mo0.3Cu0.7Sr2ErCu2Oy system associated with an oxidation reaction leading from a non-superconducting to a superconducting state has also been investigated by means of x-ray photoelectron spectroscopy (XPS). XPS measurements show the predominance of the MoV oxidation state over the MoVI one in the AP sample; annealing under flowing oxygen enhances both the MoVI and CuII amounts. The AP sample shows the existence of ferromagnetic clusters originated from the short-range magnetic correlations of the paramagnetic MoV cations. On the other hand, all the oxygenated samples are not magnetic but superconducting. The high-pressure oxygenated sample shows the highest superconducting transition temperature of TC = 84 K. A partial oxygen ordering in the (Mo/Cu)O1+? chain and a decrease in the charge transfer energy after oxygenation induces superconductivity in the oxygenated samples. | |
Internacional
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Si |
JCR del ISI
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Si |
Título de la revista
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Superconductor Science & Technology |
ISSN
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0953-2048 |
Factor de impacto JCR
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2,796 |
Información de impacto
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Datos JCR del año 2013 |
Volumen
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28 |
DOI
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Número de revista
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Desde la página
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04507 |
Hasta la página
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045017 |
Mes
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SIN MES |
Ranking
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