Semiclassical approximation for the specific heat of non-crystalline solids at intermediate temperatures

Abstract

The origin of the broad maximum in the specific heat (c _P) of glassy systems in the c _P/T ³ representation, in correspondence with the boson peak, has been described from a semiclassical perspective. A new model, based in the Debye approximation, taking into account the anharmonic vibrations of correlated atoms, is proposed. The theoretical predictions are shown to be in good agreement with the experimental data obtained in several glass samples in the temperature range 2–80 K.

Acknowledgements

We are grateful to F.G. Gandra, A.N. Medina and L.M. da Silva (Campinas, Brazil) for assistance in the specific heat measurements. The authors are grateful to the Brazilian Agencies FAPESP, CAPES, CNPq and Fundação Araucária for the financial support of this work.