The microstructural characteristics of the deformed nanocrystalline cobalt

The microstructure of the deformed nanocrystalline cobalt was studied by X-ray diffraction and transmission electron microscopy. It was discovered that after cold-rolled deformation the X-ray diffraction peak of the cobalt was narrowed. However, no grain growth of cobalt was observed in the TEM, indicating that the narrowing of the X-ray diffraction peak does not result from the growth of grain size. These results conflict with the acknowledged viewpoint that the plastic deformation can broaden the X-ray diffraction peak, owing to the formation of dislocations and stack faults. The results may be due to the production and activity of vacancies and vacancy-clusters.