Anomalous Vibrational Properties Induced by Surface Effects in Capped Pt Nanoparticles
详细信息 查看全文
- 作者：Lisandro J. Giovanetti ; José ; M. Ramallo-Ló ; pez ; Fé ; lix G. Requejo ; Domingo I. Garcia-Gutierrez ; Miguel Jose-Yacaman ; Aldo F. Craievich
- 刊名：Journal of Physical Chemistry C
- 出版年：2007
- 出版时间：May 31, 2007
- 年：2007
- 卷：111
- 期：21
- 页码：7599 - 7604
- 全文大小：228K
- 年卷期：v.111,no.21(May 31, 2007)
- ISSN：1932-7455
文摘
The Debye temperature of Pt nanoparticles (NP) capped in PVP-K30 with an average diameter of 3 nm wasdetermined from extended X-ray absorption fine structure measurements between 20 and 373 K. The sizedistribution of the NP was determined by high-resolution transmission electron microscopy, high-angle annulardark field, and small-angle X-ray scattering. We have experimentally established that the Debye temperatureof truncated cuboctahedron, capped Pt NP is 70 K higher than that of bulk Pt metal. The rather high valueof the Debye temperature of nanosized-capped Pt crystals is related to surface Pt-Pt contraction effects inconjunction with capping interactions. This finding evidences that the vibrational behavior of nanostructurematerials differs markedly from that of materials in bulk form.