Produção Nacional
Revisado por pares
Anomalous Vibrational Properties Induced by Surface Effects in Capped Pt Nanoparticles
2007; American Chemical Society; Volume: 111; Issue: 21 Linguagem: Inglês
10.1021/jp068419k
ISSN1932-7455
AutoresLisandro J. Giovanetti, J. Lopez, Félix G. Requejo, Domingo I. García-Gutiérrez, Miguel José‐Yacamán, A. F. Craievich,
Tópico(s)Chemical and Physical Properties of Materials
ResumoThe Debye temperature of Pt nanoparticles (NP) capped in PVP-K30 with an average diameter of 3 nm was determined from extended X-ray absorption fine structure measurements between 20 and 373 K. The size distribution of the NP was determined by high-resolution transmission electron microscopy, high-angle annular dark field, and small-angle X-ray scattering. We have experimentally established that the Debye temperature of truncated cuboctahedron, capped Pt NP is 70 K higher than that of bulk Pt metal. The rather high value of the Debye temperature of nanosized-capped Pt crystals is related to surface Pt−Pt contraction effects in conjunction with capping interactions. This finding evidences that the vibrational behavior of nanostructure materials differs markedly from that of materials in bulk form.
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