Are there phase transitions in liquid metallic alloys?

Abstract

Recently, resistivity measurements of some liquid metals and metallic alloys have been obtained using an electrode technique. A marked change of the slope of the resistivity versus temperature has been observed following the history of the alloy in the liquid state and the authors conclude that there are “structural transitions in the melt”. It is of interest to examine such effects and to try to understand their origin. In this work, the resistivities of several liquid metals and metallic alloys were measured as a function of temperature. Particular attention was given to the history of the alloy, including solidification and melting conditions. We also observed “anomalies”. Our experiments lead us to conclude that they must very probably be attributed to the release of gas or vapour bubbles in the liquid alloy at the first heating, resulting from the decomposition of compounds like oxides or hydroxides of the metals, but not from a phase transition in the liquid metallic state involving “breaking” Sn–Sn covalent bands.

Keywords:

• liquid metallic alloy
• resistivity
• phase transition
• anomaly indium
• bismuth
• lead
• liquid phase