STRUCTURE OF SPUTTER-DEPOSITED V-SI AMORPHOUS-ALLOYS

The metal-insulator transition of VxSi100-x amorphous alloys were inve stigated from a structural point of view. The partial Si-Si and V-Si p air correlations for the V-Si amorphous alloys below 37 at.% V are der ived from a combination of S(Q)s obtained by X-ray and neutron diffrac tions. New Si-Si neighbour distribution peak at about 2.85 Angstrom, w hich is not existent in pure amorphous Si, is observed to grow up by a lloying V with Si. The coordination numbers of Si atoms and V atoms ar ound a Si atom vary as a function of the V concentration. Especially, it is noteworthy that the rate in the variation abruptly changes at 18 -19 at.% V. By comparing the dependence of the electrical conductivity with the V concentration, it can be concluded that the sudden change of the atomic rearrangement is responsible for triggering the metal-in sulator transition.