CHEMICAL AND TOPOLOGICAL SHORT-RANGE ORDER OF AMORPHOUS TI-SI ALLOYS

Amorphous Ti100-xSix alloys (13 less than or equal to x less than or equal to 60) were produced by sputtering. Their partial structure factors were determined by X-ray and neutron diffraction. The Bhatia-Thornton density-concentration correlation function G(NC)(R) was calculated by a cluster relaxation model. Three-dimensional atomic clusters were produced by the Reverse Monte Carlo method. These clusters were analyzed in terms of trigonal prismatic arrangements as a structural unit. In amorphous Ti75Si25 and Ti87Si13 those Si-atoms which are surrounded by 9 Ti-atoms in the first coordination shell prefer trigonal prismatic arrangements. In the atomic clusters of amorphous Ti59Si41, Ti49Si51, and Ti40Si60, however, no preference of trigonal prisms was found.