Springer Online Journal Archives 1860-2000
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Abstract An X-ray diffraction radial-distribution study of Cu0,05As0,50Te0.45 (MI) and Cu0.15As0.40Te0.45 (MII) amorphous alloys obtained by the melt-quench method has been performed. The short-range order proposed from the radial distribution function (RDF) interpretation was calculated from a theoretical expression that takes into account the variation with s (scattering vector modulus) of the atomic scattering factor, and approximating it to polynomial functions. The local order of both alloys presents a deviation from the covalent character of the arsenic and tellurium elements bound to copper, increasing the mean coordination and not fitting the “octet” rule. For an in-depth study of the structural characteristics, tridimensional models were built by computer simulation of an X-ray diffraction experiment. Refinement was carried out by the Metropolis-Monte Carlo method with some modifications. The basic structure of both models may be described by a network of tetrahedra centred on copper and arsenic atoms. As both clusters are intermingled, the network connectivity is increased. Both models present a certain number of tellurium atoms with dangling bonds with average bonding distances above the mean value in the model which, together with the copper concentration, may be responsible for its decreased electrical resistivity.
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