Short-Range Order in a Ni63.7 Zr36.3 Amorphous Alloy. Effects of Structural Relaxation

Abstract

The authors present a complete study of the changes in topological and chemical short-range order produced by two stages of structural relaxation in the amorphous alloy Ni/sub 63.7/Zr/sub 36.3/. They present preliminary results for an isothermal heat-treatment which just eliminates the broad (irreversible) exothermic phenomenon. The three partial structure factors (PSF) were determined from neutron diffraction experiments on three isotopically substituted samples: /sup nat/Ni/sub 63.7/Zr/sub 36.3/, /sup 60/Ni/sub 63.7/Zr/sub 36.3/ and /sup 62/Ni/sub 39.2//sup 60/Ni/sub 24.5/Zr/sub 36.3 / ( =0, `zero alloy'). The normalised determinant of the equations to be solved to obtain the PSF is exceptionally high, allowing a direct determination of the three PSF from the data without using constraints. The `zero alloy' yields a direct determination of the Bhatia-Thornton partial structure factor S/sub CC/(q) which describes the chemical short-range order.