Nanostructures and Nanomaterials: Characterization and Properties
Nanostructures and Nanomaterials: Characterization and Properties. Instructors: Prof. Anandh Subramaniam and Prof. Kantesh Balani, Department of Materials Science and Engineering, IIT Kanpur. This course will provide an overview of nanostructures evincing their fascinating properties (mechanical, optical, electromagnetic, chemical, and biological) unseen otherwise. The hierarchical development from nano to macro length scale, and its adoption in nature (biomimicking) will also be discussed. Understanding the change in crystal structure and defects therein as one goes from bulk to nano length scale will be utilized to construct structure-mechanism-property-performance maps. Thermodynamics resulting from the size effects at nano-length scales will also be considered. Structural, phase, microstructural and mechanical characterization techniques will be dealt in detail.
(from nptel.ac.in)
Lecture 17 - Dislocations
Weakening of a crystal by dislocations (concept of theoretical shear strength); Motion of dislocations and plasticity by slip; Dislocations in finite crystals: image forces; Dislocations in nanocrystals; Strengthening mechanisms; Image forces in nanocrystals: critical size for dislocation free crystals; Effect of grain size on mechanism of plastic deformation (twinning versus slip).