Neutron diffraction study of gallium nanostructured within a porous glass

Abstract

Neutron diffraction studies of structure and atomic vibrations in gallium nanoparticles with the size of 13 nm embedded into a porous glass were performed. At crystallization of gallium, which at room temperature is in a liquid state, the texture effects were observed. The modeling of texture by generalized spherical harmonics allowed us to measure the temperature dependence of the mean-square displacement. It was shown that the contribution of acoustic vibrations in the phonon spectrum of conned gallium is dominant. The Debye temperature of nanostructured gallium appeared to be close to that for the bulk. The Grüneisen constant was found to be strongly reduced with respect to the bulk, as well as the thermal expansion coefficient. It was demonstrated that texture affects physical properties, in particular, superconductivity through inner stresses. © 2012 American Physical Society.