Experimental investigation of the waterlike density anomaly in the liquid Ge15Te85 eutectic alloy -: art. no. 104202

This paper presents an analysis of the structural changes undergone by liquid Ge15Te85 alloys in a 150 K temperature range above the eutectic temperature. This structural change is characterized by strong and anomalous variations of thermodynamic quantities among which are the density, the heat capacity, and the isothermal compressibility. The total structure factors were measured by neutron scattering on the D4B spectrometer at the ILL (Grenoble). The analysis of the thermodynamic and neutron scattering data suggests that the structural change undergone by the liquid mainly consists in a modification of the first-neighbor shell of the Ge atoms. With increasing temperature an increasingly large number of GeTe bonds become shorter, leading to a more compact local environment with a smaller atomic volume. The relation with the alphareversible arrowbeta transition of the solid GeTe compound is discussed.