Short-range order in undercooled liquid metals

Undercooled liquid metals are a metastable slate of matter with properties which fan be investigated by electromagnetic levitation. To obtain insight into the short-range order of undercooled liquid metals, we have installed an electromagnetic levitation facility at a synchrotron source. In this paper, we report the results obtained by a combination of electromagnetic levitation and the extended X-ray absorption fine structure (EXAFS) technique. Measurements have been carried out on potentially ferromagnetic Liquid Co-Pd alloys, and on Al-Cu-Co alloys of quasicrystal forming composition. In spite of the experimental difficulties, spectra could be obtained over a wide temperature range and the relevant physical parameter, such as the nearest-neighbour distance: could be determined quantitatively. At the melting point, the Go-Co nearest neighbour distance is 2.50 Angstrom, while the Co-Pd nearest neighbour distance is 2.69 Angstrom. (C) 1998 Elsevier Science B.V. All rights reserved.