Regensburg 2007 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 14: Si/Ge

HL 14.3: Vortrag

Montag, 26. März 2007, 16:30–16:45, H14

Study of the disproportionation in bulk amorphous germanium monoxide — •Andreas Schacht¹, Christian Sternemann¹, Achim Hohl², Henning Sternemann¹, Michael Paulus¹, and Metin Tolan¹ — ¹Dept. Phys. / DELTA, University of Dortmund, D-44221 Dortmund — ²Institute for Materials Science, Darmstadt University of Technology, D-64287 Darmstadt

Measurements of the x-ray absorption near-edge structure at the Ge K-edge of ex-situ annealed amorphous germanium monoxide samples, i.e. GeO_x (x≈ 1), were accomplished in partial fluorescence yield mode at BL9 of the synchrotron radiation source DELTA utilising a spectrometer in Rowland geometry. A systematic temperature dependence was observed for the near-edge structure within the first 10 eV above the Ge K-edge and could be related to the disproportionation process of amorphous germanium monoxide into germanium and germanium dioxide. The onset of the observed disproportionation process was estimated to a temperature of 245±25^∘ C. Full disproportionation into germanium and germanium dioxide was observed at an annealing temperature of 525±50^∘ C. Also crystallisation of samples sets in for temperatures above 525^∘ C which could be confirmed by x-ray diffraction.