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www.msm.cam.ac.uk/phase-trans/teaching.html Crystallography Lecture notes Many other things. Crystallography. H. K. D. H. Bhadeshia. Introduction and point groups Stereographic projections Low symmetry systems Space groups Deformation and texture Interfaces, orientation relationships
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www.msm.cam.ac.uk/phase-trans/teaching.html Crystallography Lecture notes Many other things
Crystallography H. K. D. H. Bhadeshia Introduction and point groups Stereographic projections Low symmetry systems Space groups Deformation and texture Interfaces, orientation relationships Martensitic transformations
Liquid Crystals (Z. Barber)
Bravais Lattices • Triclinic P • Monoclinic P & C • Orthorhombic P, C, I & F • Tetragonal P & I • Hexagonal • Trigonal P • Cubic P, F & I
body-centred cubic (ferrite) face-centred cubic (austenite)
Fe Ru 6d 2s Os Hs
-35 -45 -55 -65 Cubic-P Diamond cubic Cohesive energy (eV/atom) Pure iron Hexagonal-P b.c.c c.c.p h.c.p 0.8 1.0 1.2 1.4 1.6 Normalised volume Paxton et al. (1990)
Amorphous - homogeneous, isotropic Crystals - long range order, anisotropic Crystals - solid or liquid Crystals - arbitrary shapes Polycrystals Lattice, lattice points Unit cell, space filling Primitive cell, lattice vectors Bravais lattices Directions, planes Weiss zone rule Symmetry Crystal structure Point group symmetry Point group symbols Examples
1/2 1/2 1/2 1/2 Crystal Structure
lattice + motif = structure primitive cubic lattice motif = Cu at 0,0,0 Zn at 1/2, 1/2, 1/2
1/4 1/4 1/4 1/4 1/4 3/4 3/4 3/4 3/4 Lattice: face-centred cubic Motif: C at 0,0,0 C at 1/4,1/4,1/4
1/4 1/4 3/4 3/4
3/4 1/4 1/4 3/4 Lattice: face-centred cubic Motif: Zn at 0,0,0 S at 1/4,1/4,1/4