On the origin of enhanced specific heat in nanocrystalline platinum

Abstract
Nanocrystalline platinum has been investigated by differential scanning calorimetry and simultaneous thermal analysis as well as thermogravimetric analysis and mass spectroscopy in order to study the origins of enhanced specific heat of this material. The possible reasons for the enhanced specific heat are discussed in terms of anharmonic contributions caused by a reduced atomie density in grain boundaries and the presence of light-element impurities. From the experimental results it is suggested that the influence of the light-element impurities exceeds by far the anharmonic contributions from grain boundaries. Furthermore, a auasiharmonic Debye model of the grain boundary indicates that the mean grain-boundary volume expansion is less than 20%.

This publication has 8 references indexed in Scilit: