Ordering and disordering in anisotropic L10-FePd

Abstract

ABSTRACTNearly equiatomic FePd (Fe-52at.%Pd) alloys have been deformed by cold-rolling to 60% thickness reduction. Ordering and disordering was studied during isochronal and isothermal annealing by residual resistometry (REST) in the deformed as well as in the recrystallized state. In both cases a first order phase transition with a broad thermal hysteresis is observed. Resistivity values corresponding to thermal equilibrium of LRO-states, however, result lower in the deformed case. This is interpreted as a consequence of internal stresses leading to a preference of one variant of ordered domains and consequently to a higher degree of LRO.A detailed study by an isothermal small-step annealing treatment yields two counteracting exponential processes during order-order relaxation with an activation energy of 2.7eV and 2.4eV, respectively.