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Título:
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Structure, phase transformations, and defects of HfO? and ZrO? nanoparticles studied by ^(181)Ta and ^(111)Cd perturbed angular correlations, ^(1) H magic-angle spinning NMR, XPS, and x-ray and electron diffraction
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Autores:
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Forker, M. ;
Presa Muñoz del Toro, Patricia de la ;
Hoffbauer, W. ;
Schlabach, S. ;
Bruns, M. ;
Szabó, D. V.
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Tipo de documento:
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texto impreso
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Editorial:
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American Physical Society, 2008-02
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Dimensiones:
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application/pdf
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Nota general:
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info:eu-repo/semantics/openAccess
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Idiomas:
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Palabras clave:
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Estado = Publicado
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Materia = Ciencias: Física: Física de materiales
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Materia = Ciencias: Física: Física del estado sólido
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Tipo = Artículo
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Resumen:
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Structure, phase transformations, grain growth, and defects of bare and alumina-coated nanoparticles of HfO? and ZrO? synthesized in a microwave-plasma process have been investigated by x-ray diffraction (XRD), transmission electron microscopy (TEM), and perturbed angular correlation (PAC) spectroscopy. The PAC technique was used to measure the electric quadrupole interactions (QIs) of the nuclear probes ^(181)Ta and ^(111)Cd in nanocrystalline HfO? and ZrO? as a function of temperature. For comparison, the QI of ^(181)Ta in the bulk oxides was determined in the same temperature range 300 K ? T ? 1550 K. The oxygen-metal ratio of the as- ynthesized particles was determined by x-ray photoelectron spectroscopy to be in the range 1.4 ? x ? 1.8. A hydrate surface layer with a hydrogen content of 5–10 wt %, consisting of chemisorbed hydroxyl groups and organic precursor fragments, was detected by ^(1) H magic-angle spinning NMR. XRD and TEM show that bare n-ZrO?, Al?O?-coated n-ZrO?, and Al?O?-coated n-HfO? are synthesized in the tetragonal or cubic modification with a particle size d
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En línea:
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https://eprints.ucm.es/45531/1/DeLaPresaP%2008%20libre.pdf
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