Self diffusion anomaly in ferromagnetic metals: A density-functional-theory investigation of magnetically ordered and disordered Fe and Co

The temperature (7) dependent self-diffusion coefficients (D) in Fe and Co are calculated from first-principles, across the Curie temperature (T,), employing a density functional theory approach based on a recently developed spin-wave method for modeling the paramagnetic state. Calculated results for D(T) are shown to accurately reproduce measured values for T/T-c, ranging from 0.7 to 1.1, including the anomaly in the Arrhenius plot for Fe near T-c. An analysis of calculated results in Mn, Fe and Co suggests that the magnitude of the effect of magnetic disorder on D is correlated with d band filling and the transition from weak to strong ferromagnetism.(C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.