Structural characterization of amorphized InP: Evidence for chemical disorder

Extended x-ray absorption fine-structure measurements at the In K edge of amorphous InP are presented. The presence of chemical disorder in the form of like-atom bonding has been unambiguously demonstrated in stoichiometric InP amorphized by ion implantation. In-In bonding comprised 14% +/- 4% of the In-atom constituent bonds. Also, relative to the crystalline value of four P atoms, an increase in the total In coordination number to 4.16+/-0.32 atoms was observed for the amorphous phase, as composed of 3.56+/-0.19 P and 0.60+/-0.13 In atoms. Experimental results were consistent with recent ab initio structural calculations and, furthermore, demonstrated that amorphous InP is best described by a Polk-like continuous random network, containing both even- and odd-membered rings. (C) 1999 American Institute of Physics. [S0003-6951(99)03112-5].