title: On the relation between the microscopic structure and the sound velocity anomaly in elemental melts of groups IV, V, and VI.
abstract: The sound velocity of some liquid elements of groups IV, V, and VI, as reported in the literature, displays anomalous features that set them apart from other liquid metals. In an effort to determine a possible common origin of these anomalies, extensive neutron diffraction measurements of liquid Bi and Sb were carried out over a wide temperature range. The structure factors of liquid Sb and Bi were determined as a function of temperature. The structure of the two molten metals was carefully analyzed with respect to peak locations, widths, and coordination numbers in their respective radial distribution function. The width of the peaks in the radial distribution functions was not found to increase and even decreased within a certain temperature range. This anomalous temperature dependence of the peak widths correlates with the anomalous temperature dependence of the sound velocity. This correlation may be accounted for by increased rigidity of the liquid structure with temperature. A phenomenological correlation between the peak width and the sound velocity is suggested for metallic melts and is found to agree with available data for normal and anomalous elemental liquids in groups IV-VI.
authors.affiliation: Department of Materials Engineering, Ben Gurion University of the Negev, Beer-Sheva 84105, Israel. yargreen@zahav.net.il
authors.forename: Yaron
authors.initials: Y
authors.lastname: Greenberg
authors.forename: Eyal
authors.initials: E
authors.lastname: Yahel
authors.forename: El'ad N
authors.initials: EN
authors.lastname: Caspi
authors.forename: Brigitte
authors.initials: B
authors.lastname: Beuneu
authors.forename: Moshe P
authors.initials: MP
authors.lastname: Dariel
authors.forename: Guy
authors.initials: G
authors.lastname: Makov