Thermal morphological evolution of platinum nano-particles in Pt-Al2O3 nano-composites

M Maaza , O Nemraoui , C Sella , Jacques Lafait (1) , Alain Gibaud , V Pischedda (2)

1 LOS - Laboratoire d'optique des solides
2 WITS - University of the Witwatersrand [Johannesburg]

Temperature morphological evolution of nonpercolated granular nano-structures of platinum nano-particles embedded in an insulating alumina matrix was investigated by X-rays scattering in grazing angle reflection mode. In the investigated temperature range of 298-823 K, it was found that the annealing treatment tends to increase the Pt nano-particles' size and to produce a quasi-mono-disperse Pt nano-particles followed by a reduction of the barrier thickness between them. The percolation temperature is estimated to be of the order of 890 K. Using the rate constant governing the growth of the Pt nano-particles, the corresponding activation energy was determined to be about 90 kJ/mol. (c) 2005 Elsevier B.V. All rights reserved.

Mots clés: nano-composites; percolation process; growth process; small angle X-ray scattering; grazing incidence

Domaines: Matière Condensée [cond-mat]

M Maaza, O Nemraoui, C Sella, Jacques Lafait, Alain Gibaud, et al.. Thermal morphological evolution of platinum nano-particles in Pt-Al2O3 nano-composites. Physics Letters A, 2005, 344 (1), pp.57-63. ⟨10.1016/j.physleta.2005.06.072⟩. ⟨hal-01281516⟩