Stereographic projections Low symmetry systems Space groups Deformation and texture Interfaces orientation relationships Martensitic transformations Crystallography H K D H Bhadeshia wwwphasetransmsmcamacukteachinghtml ID: 1022266
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1. Introduction and point groupsStereographic projectionsLow symmetry systemsSpace groupsDeformation and textureInterfaces, orientation relationshipsMartensitic transformationsCrystallographyH. K. D. H. Bhadeshiawww.phase-trans.msm.cam.ac.uk/teaching.html
2. 1/21/21/21/2Crystal Structure
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4. lattice + motif = structureprimitive cubic latticemotif = Cu at 0,0,0 Zn at 1/2, 1/2, 1/2
5. 1/41/41/41/41/43/43/43/43/4Lattice: face-centred cubicMotif: C at 0,0,0 C at 1/4,1/4,1/4
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7. 1/41/43/43/4
8. x
9. 1/41/43/43/4Lattice: face-centred cubicMotif: Zn at 0,0,0 S at 1/4,1/4,1/4
10. candidate for ultra violet light-emitting diodecould be useful in the purification of water
11. cubic gallium nitridehas the potential of more efficient green coloured light-emitting diodes than the normal hexagonal versionLee LY. Cubic zincblende gallium nitride for green-wavelength light-emitting diodes. Materials Science and Technology. 33 (2017) 1570-83.
12. source of flourine,flux in aluminium smelting
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15. Rotation axes2 diad3 triad4 tetrad6 hexad
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17. CENTRE OF SYMMETRY
18. Point groups2m
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20. Sulphur tetraflourideWater and sulphur tetrafluoride have same point symmetry and hence some identical vibration modes - similar lines in spectra
21. Alexander Van Driessche / CC BY (https://creativecommons.org/licenses/by/3.0)Gigantic gypsum in the cave of crystals,Naica, MexicoGypsum used in construction materials.
22. Gypsum 2/m
23. Martin Lister,De Fontibus Medicatis Angliae (1682) hydrated magnesium sulphateEpsom salts, apparently have palliative properties.
24. Epsomite222
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26. 3mbishop
27. castle4mm
28. 1 µmhexagonalaluminiumnitrideCourtesy Shaumik Lenka
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30.
31. without high-order axes
32. with high-order axes
33.