Investigation of sluggish diffusion in FCC Al0.25CoCrFeNi high-entropy alloy

To validate the 'sluggish diffusion' in high-entropy alloys, interdiffusion coefficients of individual elements and tracer diffusion coefficient of Ni were experimentally determined in FCC Al0.25CoCrFeNi alloy. The tracer diffusion coefficient was determined without the application of radio-tracers using a novel analytical method proposed by Belova et al. based on linear response theory coupled with Boltzmann-Matano approach and Gaussian distribution function. Sluggish diffusion kinetics was not observed in alloys with higher configuration entropy in comparison to alloys with lower configuration entropy. Correspondingly, potential energy fluctuations in alloys with higher configuration entropy may not always result in anomalously slow diffusion kinetics. IMPACT STATEMENT Diffusion is determined not to be necessarily sluggish in Al0.25CoCrFeNi high-entropy alloy by experimental measurement of chemical and tracer diffusion coefficients.