Order-Disorder Transition inNi3Fe Studied by Mössbauer Spectroscopy

Abstract
Using Mössbauer spectroscopy, the order-disorder transition in stoichiometric Ni3Fe was investigated "at temperature" in the transition region between 770 and 785 K. Detailed analysis of the linewidth showed that the phase transition is of first-order character and proceeds inhomogeneously via the nucleation and growth mechanism. Nucleation of the ordered phase is suppressed, leading to a temperature hysteresis of 10 K. In the two-phase region composition segregation has been observed.