Publications: Articles
2012 | |
Articles: | |
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Chemistry of materials,
24 (3):2429-2432
2012
DOI: 10.1021/cm301179x
Equipe: Département SI2M : Microstructures et Contraintes |
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Journal of Physics and Chemistry of solids,
73(4):554-558
2012
ISSN: 0022-3697
Resume: Zr1-xWx nanocrystalline films of Zr-W solid solutions and ZrW2 Laves phase were synthesized by magnetron co-sputtering. Large values of the H/E ratio up to 0.09 are observed for grain sizes in the nanometer range along with a hardness above 10 GPa and Young's modulus below 230 GPa. H/E values are correlated with the developed surface of grain boundaries suggesting an elastic deformation mostly handled by the grain boundaries. This is associated to friction coefficients comparable to those of metallic glass surfaces. In contrast to fragile bulk Laves phases, no cracks were detected at the film surface after indentation and scratch test of nanocrystalline ZrW2. The friction coefficient of such films against diamond tip was in the range 0.08-0.15, similarly to metallic glass surfaces. (C) 2011 Elsevier Ltd. All rights reserved. Equipe: Département SI2M : Microstructures et Contraintes |
2009 | |
Articles: | |
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Intermetallics,
17(6):421-426
2009
ISSN: 0966-9795
Resume: WxZr1-x thin films were deposited at room temperature on glass substrates by co-sputtering tungsten and zirconium targets in argon. The composition was found in the range 0 <= x <= 0.81. The grain size deduced from X-ray diffraction analysis ranged from 1.3 nm to 16 nm depending on the composition. The events in the resistivity, optical reflectivity and thickness evolutions were correlated with the X-ray diffraction analysis. Depending on the composition, the local organization can be attributed to a nanocrystalline solid solution of W in Zr, to a nanocomposite structure involving ZrW2 nanograins embedded in an amorphous matrix. to ZrW2 Laves phase nanograins and to a nanocrystalline solid solution of Zr in W. For 0 < x <= 0.72, the equivalent grain size is very small (less than 2 nm) and the evolution of the resistivity can be fitted by the estimated volume of the material perturbed by the grain boundaries. (C) 2008 Elsevier Ltd. All rights reserved. Equipe: Département SI2M : Microstructures et Contraintes |