Atomic-level characterisation of the structure of amorphised GaAs utilising EXAFS measurements

Extended X-ray absorption fine structure (EXAFS) analysis has been used to determine the structural parameters of stoichiometric, amorphised GaAs. Rel ative to a crystalline sample, the nearest-neighbor bond length and Debye-W aller factor both increased for amorphous material. In contrast, the coordi nation numbers about both Ga and As atoms in the amorphous phase decreased to similar to 3.85 atoms from the crystalline value of four. Similar trends were evident for amorphised Ge excluding the coordination number which did not deviate from the crystalline value. The structural parameters of amorp hised GaAs and Ge have been discussed in terms of the multi- and mono-eleme ntal nature, respectively, of the two materials. (C) 1999 Elsevier Science B.V. All rights reserved.