Structure of Materials. Instructor: Dr. Anandh Subramaniam, Department of Materials Science and Engineering, IIT Kanpur. Atomic arrangement in crystalline solids, defects in crystalline solids, microstructure evolution, quantification of microstructures. Topics includes: bonding in materials; geometry of crystals: symmetry, lattices; Miller indices; crystal structures; defects in crystals; diffusion; phase diagrams; phase transformations; and effect of microstructure on properties.
(from nptel.ac.in)
Lecture 11 - 7 Crystal Systems (cont.), Ideal versus Real Crystals, Microstructure
Crystal systems: 7 crystal systems (tetragonal, orthorhombic, hexagonal, trigonal, monoclinic, triclinic). Minimum symmetry requirement for the 7 crystal systems. Why do we need to consider 'arbitrary' motifs? Advanced ('official') definition of a crystal: crystal = symmetry + space group (+ asymmetric unit). Ideal versus real crystals (ideal crystal - real crystal - microstructure - component). 'Functional' definition of microstructure: [(microstructure = phases + defects + residual stress) and their distributions].