Abstract
The reverse Monte Carlo and Voronoi-Delaunay analyses have been applied to characterize the intermediate-range fluctuations near the metal-nonmetal transition in expanded liquid Hg. An analysis of voids acts as a useful adjunct to the normally discussed structural properties in interpreting the origin of intermediate-range fluctuations in the expanded liquids. The results for Hg-based and void-based partial pair distribution functions and the partial coordination number distributions reveal that the metallic domains (M domains) are built with packing of tetrahedral blocks. The M domains transform into the nonmetallic domains (NM domains) creating large voids (L voids) in radius, which are supported by the network linked with tetrahedral blocks containing small voids (S voids) in radius at densities of , where the coordination number is rapidly reduced below six. The estimated density variations in from “domain model” and “void model” exhibit a peak around , which indicates that M domains and NM domains coexist near the metal-nonmetal transition region. There appears the prepeak at in the partial structure factor of L voids around the L voids, , suggesting the chemical ordering of L voids. It follows that the intermediate-range concentration fluctuations resulting in microphase separation (clustering) of NM domains and M domains are reflected in the structural change near the metal-nonmetal transition.
9 More- Received 5 February 2009
DOI:https://doi.org/10.1103/PhysRevB.80.014201
©2009 American Physical Society