Examination of the electronic structure of crystalline and liquid Al versus temperature by in situ electron energy-loss spectroscopy (EELS)

Electron energy-loss near-edge structure (ELNES) analysis using in situ heating in a transmission electron microscope (TEM) was performed to compare the electronic structure of crystalline and liquid Al versus temperature. It was found that the ELNES features in the L2,3 edges of crystalline and liquid Al are qualitatively similar, but that the edge threshold is modified and certain features in the energy range between 102 and 115 eV vanish in the liquid, indicating that partial DOS is quantitatively different. Broadening of the L2,3 edge maximum for Al with temperature indicates a decay in the centrifugal barrier for the 2p electrons with increasing temperature. Comparison between the ELNES edge in supercooled liquid and crystalline Al at the same temperature of 600 °C shows that the degree of order, i.e., crystallinity, plays an important role in determining the DOS. The ELNES edge of supercooled liquid Al closely resembles that of superheated liquid Al.