In-situ extended energy-loss fine structure analysis of the solid and liquid phases in sub-micron Al particles

Abstract

Articles you may be interested inReactions of liquid and solid aluminum clusters with N2: The role of structure and phase in Al114 +, Al115 +, and Al117 + 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 J. Appl. Phys. 110, 043515 (2011); 10.1063/1.3624735Melting and supercooling studies in submicron Al particles using valence electron energy-loss spectroscopy in a transmission electron microscope Extended energy-loss fine structure (EXELFS) analysis was used to study the behavior of the nearest-neighbor atomic distance and thermal vibration behavior of pure Al particles heated and cooled through the melting temperature in situ in a transmission electron microscope. The results show that the increase in first nearest-neighbor distance for solid Al with temperature compares reasonably well with calculated values based on thermal expansion and that anharmonic thermal vibrations lead to an asymmetry in the Gaussian shape of radial-distribution function (RDF) peaks with temperature. In addition to thermal disorder, structural disorder also contributes to an increased asymmetry in the RDF peaks in liquid Al. Comparison of the first nearest-neighbor distance change with the inverse volume plasmon energy obtained from a previous study shows that the nearest-neighbor distance does not follow the same hysteresis as the plasmon energy during supercooling of liquid Al. The apparent contraction in the nearest-neighbor distance observed during supercooling is explained as due to the asymmetry in the RDF peaks at high temperatures caused by the thermal vibrations, possibly combined with the formation of local (icosahedral) clusters in the liquid.

Determining the Volume Expansion at Grain Boundaries Using Extended Energy-Loss Fine Structure Analysis

“…EXELFS has been previously used to study changes in the n.n. distance and the thermal vibration behavior of pure Al during heating and cooling through the melting temperature using the L 2,3 edge (Palanisamy & Howe, 2011). The increase in n.n.…”