Chemical short-range order in liquid Ni-Cu.

Neutron diffraction in combination with isotopic substitution on the zero-scatterer 62 Ni 43 63 Cu 57 shows indications for chemical short-range order in the stable liquid as evidenced by oscillations in the concentration-concentration structure factor S CC (q). This points towards a non-ideal solution behavior of Ni-Cu contrary to common believe but in agreement with measurements of free enthalpy of mixing. The temperature dependence of S CC at small momentum transfer provides evidence of critical compositional fluctuations in Ni 43 Cu 57 melts.&#xD.