SHORT-RANGE ORDER IN AMORPHOUS NI50TA50 ALLOYS BY MEANS OF X-RAY AND NEUTRON-DIFFRACTION

In the present work, amorphous Ni50Ta50 samples with a high crystalliz ation temperature of 985 K were investigated. To evaluate the three pa rtial structure factors, an X-ray diffraction experiment with Ni50Ta50 and two neutron diffraction experiments with Ni50Ta50 and with Co10Ni 40Ta50, respectively, were performed. The nearest neighbour distance i s d = 2.82 angstrom for Ni-Ni, d = 2.91 angstrom for Ta-Ta, and d = 2. 44 angstrom for Ni-Ta. The coordination numbers are N(NiNi) = 4.9, N(T aTa) = 8.2 and N(NiTa) = 6.0. The chemical short-range order and the c hemical bounding in a-Ni50Ta50 are reported.