Eur. Phys. J. B 51, 209-213 (2006)
https://doi.org/10.1140/epjb/e2006-00214-x

Fine structure effects and phase transition of Xe nanocrystals in Si

¹ Dipartimento di Fisica e Astronomia, Universitá di Catania; MATIS - Istituto Nazionale di Fisica della Materia, via Santa Sofia 64, 95123 Catania, Italy
² ESRF, European Synchrotron Research Facility, B.P., 220 38043 Grenoble Cedex, France

Corresponding author: ^a giuseppe.faraci@ct.infn.it

Received: 30 January 2006
Revised: 7 April 2006
Published online: 2 June 2006

Abstract

We report on an X-ray diffraction study performed on Xe agglomerates obtained by ion implantation in a Si matrix. At low temperature, Xe nano-crystals were formed in Si with different average sizes according to the preparation procedure. High resolution diffraction spectra were detected as a function of the temperature, in the range 15–300 K, showing evidence of fine structure effects in the growth mode of the Xe nanocrystals. We report the first experimental observation of fcc crystalline agglomerates with a lattice parameter expanded by the epitaxial condensation on the Si cavities, whereas for small agglomerates randomly oriented evidence of a contracted lattice was found. For these nanocrystals, a solid-to-liquid transition temperature, size dependent, was detected; above the transition temperature, a fluid phase was observed. Neither overpressurized clusters were detected at any temperature, nor preferential binary size distribution as reported for a metal matrix.