KINETICS OF ORDER-DISORDER TRANSFORMATIONS IN ALLOYS .3.

Calculations of specific heat vs temperature curves corresponding to measurements with finite heating rates have been carried out for alloys under various initial conditions utilizing the pair approximation of the Path Probability method of time dependent cooperative phenomena and are compared with experiments on Mg3Cd, FeCo, and Cu3Au. New experiments on Mg3Cd suitable for comparison are also presented here. The main emphases of the comparisons are (1) the appearance of a specific heat subpeak below the main specific heat peak at Tc for well annealed alloys, (2) the shift of the subpeak by a change of the heating rate, (3) the appearance of a specific heat dip for alloys quenched from higher temperatures, and (4) the appearance of two specific heat dips for highly disordered alloys quenched from above the critical point of order-disorder. Good qualitative agreement of theory and experiment is obtained in each of these four categories. © 1979 American Institute of Physics.