Coarsening behavior and coercivity in L10-ordered intermetallic Fe-Pd ferromagnets with equiaxed grain morphology

Thermo mechanical processing of equiatomic FePd has been used to establish a nearly equiaxed microstructure that consists of mono-variant L1(0) ordered grains. The technically important hard magnetic properties, e.g. coercivity, of the uniaxial ferromagnetic L1(0)-FePd with equiaxed microstructure depend on the grain size. Thus, here, the evolution of grain size during the later stages of annealing has been studied using SEM and computer assisted image analysis with the goal to determine the activation parameters for the relevant coarsening processes. Using a classical grain growth analysis the activation parameter for coarsening of the 5% largest grains in the populations of L1(0)-ordered grains in FePd has been determined as approximately 30kcal/mol.