Fq. Guo et K. Lu, MICROSTRUCTURAL EVOLUTION IN MELT-QUENCHED AMORPHOUS SE DURING MECHANICAL ATTRITION, Physical review. B, Condensed matter, 57(17), 1998, pp. 10414-10420
Microstructural evolution of an as-quenched amorphous Se sample during
ball milling was investigated by use of x-ray diffraction, a differen
tial scanning calorimeter, infrared and Raman spectroscopy, as well as
x-ray photoemission spectroscopy. It was found that the as-quenched a
morphous Se is crystallized completely into a nanocrystalline trigonal
Se phase after milling for 30 min. Further milling of the as-milled n
anocrystalline trigonal Se resulted in a transformation into another a
morphous Se phase, which exhibits a lower crystallization temperature
and a smaller crystallization enthalpy compared to those for the as-qu
enched amorphous Se according to thermal analysis. Infrared and Raman
spectroscopy measurements revealed that the as-milled amorphous Se is
mainly composed of Se-n polymeric chains that are fundamentally differ
ent from the as-quenched amorphous Se in which the Se-8 ring structure
is predominant. However, despite the phase evolution and changes in m
olecular structure in Se, x-ray photoemission measurements indicated t
hat no detectable changes in electronic properties (e.g. the density o
f valence states, the binding energies of core levels, and the charact
eristic energy loss functions) were observed among different states of
Se samples. [S0163-1829(98)00417-2].