Temperature dependence of the plasmon energy in liquid and solid phases of pure Al and of an Al-Si alloy using electron energy-loss spectroscopy

Abstract

The plasmon energy of the solid and liquid phases of pure Al, and an Al-Si alloy, was recorded as a function of temperature. For the case of pure Al, the trend in the solid and liquid phases followed the expected behavior based on a free (specific) volume change. Quantitatively, the slope of Ep versus T was -0.5 meV/K in the solid state and -2.2 meV/K in the liquid state. For the case of the Al-Si alloy, the trend in the solid phase was similar to that of pure Al, however, the trend in the liquid Al-Si phase was exactly opposite to what was observed for the pure Al liquid (i.e., 1.9 meV/K). This unexpected result is explained based on the variation, i.e., partitioning, of Si with temperature in the Al-Si alloy. © 2011 American Institute of Physics.