Journal
PHYSICAL REVIEW B
Volume 78, Issue 21, Pages -Publisher
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.78.214207
Keywords
entropy; iron alloys; metallic thin films; nanostructured materials; nuclear resonances; secondary ion mass spectra; self-diffusion; X-ray scattering; zirconium alloys
Funding
- Indo-French Center for Propmotion of Advanced Research
Ask authors/readers for more resources
Self-diffusion of Fe in amorphous Fe75Zr5 films has been studied over a wide temperature range by combining secondary-ion-mass spectrometry and nuclear-resonance reflectivity measurements. Subnanometer accuracy of nuclear-resonance reflectivity in diffusion length measurement allows quantitative determination of time-dependent diffusivity of Fe during structural relaxation. A clear correlation between diffusivity and different types of structural relaxations is observed. It is found that in both structurally relaxed and unrelaxed states, diffusive jumps occur via a collective motion of a group of atoms. However, the presence of excess free volume in unrelaxed amorphous films causes the activation energy as well as the diffusion entropy to decrease, suggesting that the average number of atoms participating in a diffusive jump is significantly less as compared to that in the fully relaxed state. The typical diffusion length involved in annihilation of free volume is 0.7 nm, which agrees with the length scale of structural fluctuations as seen in neutron- and x-ray-scattering experiments.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available