NEUTRON-DIFFRACTION STUDY OF THE STRUCTURE OF LIQUID PB-PD ALLOYS

The structure-factors S(Q) = I(a)(Q)/[f2] of liquid Pb-Pd with 0, 10, 40, 45, and 51 at.% Pd were determined from their neutron scattering patterns at 400, 600, 500, 650 and 800-degrees-C, respectively. The sample with 40 at.% Pd which forms a glass by melt-spinning was also studied at several temperatures between 500 and 900-degrees-C. By contrast with the melt-spun alloy, no splitting of the first peak in S(Q) has been observed in any of the Pb-Pd alloys studied. The Fourier transforms of Q[S(Q)-1] yielded the total reduced atomic distribution functions. G(r). The first peak in G(r) of the 40 at.% Pd alloy shows a splitting corresponding to the partial functions Pb-Pb with the interatomic distance of 3.36 angstrom and Pb-Pd with the first neighbor distance of 2.90 angstrom.