Observations of low-dimensional effects?

Recently, Lereah, Deutscher, Cheyssac and Kofman reported in Europhysics Letters on an exciting dark-field electron microscopy study of the melting of small lead particles in a silicon monoxide matrix. In this comment it will be shown that the conclusion of their paper, that the dark-field images show low-dimensional effects, cannot be unambiguously sustained. Instead an alternative explanation based on conventional bulk thermodynamics is presented. The simultaneous existence of fluid and solid lead within one and the same lead particle can be explained as being a consequence of the lead melting taking place in what is essentially a confined volume. The fact that the liquid lead «wets» the matrix only shows that the interface energy hereof is smaller than the interface energy between solid lead and the matrix.