Evidence for a temperature-driven structural transformation in liquid bismuthY. Greenberg1, 2, E. Yahel2, E. N. Caspi2, C. Benmore3, B. Beuneu4, M. P. Dariel1 and G. Makov2
1 Department of Materials Engineering, Ben Gurion University of the Negev - Beer-Sheva 84105, Israel
2 Department of Physics, NRCN - P.O. Box 9001, Beer-Sheva 84190, Israel
3 XSD and IPNS Divisions, Argonne National Laboratory - Argonne, IL, 60439, USA
4 Laboratoire Léon Brillouin (CEA-CNRS), CEA/Saclay - 91191 Gif-sur-Yvette cedex, France, EU
received 2 March 2009; accepted in final form 8 April 2009; published May 2009
published online 20 May 2009
The thermodynamic properties of liquid bismuth have been explored from the melting point to 1100 °C by high-resolution measurements of the density, the heat capacity and the static structure factor. These physical properties display a number of anomalies. In particular, we have observed evidence for the presence of a temperature-driven liquid-liquid structural transformation that takes place at ambient pressure. The latter is characterized by a density discontinuity that occurs at 740 °C. Differential thermal analysis measurements revealed the endothermal nature of this transformation. A rearrangement of liquid bismuth structure was found by neutron diffraction measurements, supporting the existence of a liquid-liquid transformation far above the liquidus.
61.25.Mv - Liquid metals and alloys.
64.70.Ja - Liquid-liquid transitions.
61.20.-p - Structure of liquids.
© EPLA 2009