Temperature dependence of the short-range order parameter and the concentration dependence of the order-disorder temperature for NiPt and NiFe systems in the improved statistical pseudopotential approximation

The calculations for the temperature dependence of the first shell short- range order (SRO) parameter for Ni₃Fe using the cubic approximation of Tahir Kheli, and the concentration dependence of order-disorder temperature T_c for NiFe and NiPt systems using the linear approximation, have been carried out in the framework of pseudopotential theory. It is shown that the cubic approximation yields a good agreement between the theoretical prediction of the α₁ and the experimental data. Results for the concentration dependence of the T_c show that improvements in the statistical pseudopotential approach are essential to achieve a good agreement with experiment.