Eur. Phys. J. B (2014) 87: 18
https://doi.org/10.1140/epjb/e2013-41024-1

Colloquium

Interstitialcy theory of simple condensed matter

Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, 61801 Illinois, USA

^a e-mail: granato@illinois.edu

Received: 20 November 2013
Received in final form: 6 December 2013
Published online: 20 January 2014

Abstract

A simple, more physical and compelling version of the Interstitialcy Theory of Simple Condensed Matter than that given previously is provided here. Also, computer simulation and direct and indirect experimental evidence is updated and reviewed. The theory is based on the properties of an interstitial in the interstitialcy, sometimes known as the dumbbell configuration. A free energy is derived, taking account of the unusually large shear susceptibility and vibrational entropy of the dumbbell to find the thermodynamic and kinetic properties of simple liquids and glasses. The connection between theory and experiment for some of the more notable properties of simple condensed matter found later is also discussed. The direct visual observation of interstitial diffusion to the surface in platinum near 20 K in irradiated thin films by Morgenstern et al. [M. Morgenstern, T. Michely, G. Comsa, Phys. Rev. Lett. 79, 1305 (1997)] is found to be sufficient compelling evidence for the interstitialcy theory.