Regensburg 2019 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 25: Transport (Diffusion, conductivity, heat)

MM 25.3: Vortrag

Mittwoch, 3. April 2019, 10:45–11:00, H46

Determination of the correlation factor for Cd solute diffusion inNi₃Al — •Bengü Tas¹, Ryan Murray², Gary S. Collins², and Sergiy V. Divinski¹ — ¹Institute of Materials Physics, University of Münster, Münster, Germany — ²Department of Physics and Astronomy,Washington State University, Pullman, WA, USA.

The correlation factor is an essential parameter for atomic transport in solids. In the case of self-diffusion, the correlation factor can be calculated easily from the lattice geometry, if the diffusion mechanism is known. Since the solute atoms modify the vacancy concentration and jump rates, measuring the solute diffusion correlation factor is a complicated task. While the first principles simulations have enabled computing the correlation factor within the framework of simplified models such as the five vacancy jump frequency model for fcc crystals, its experimental determination has never been performed. In this work, we contribute to the first measurements of the correlation factor of solute diffusion combining long-range diffusion measurements and perturbed angular correlation (PAC) experiments. The diffusion coefficient of Cd was measured at a temperature of 1073 K within the cubic L1₂ ordered Ni₃Al crystal structure and the impurity jump frequency was determined at the same temperature. The experimental findings are finally combined to evaluate the correlation factor of Cd atoms in the Ni₃Al sublattice.