Lesson 1, Topic 1
In Progress
Derivatives of FCC Lattices
In this Topic:
- Diamond structure (Si, Ge& Diamond)
- Zinc-Blende Structure
- Sodium Chloride (Rocksalt) structure
Diamond structure (Si, Ge& Diamond)
- Can be viewed as two interpenetrating fcc lattices displaced by ¼, ¼, ¼
Zinc-Blende Structure
- Identical to diamond lattice but sites are occupied by two different atoms Example: GaAs, ZnS, AlAs, InP
8 atoms per cell:
Sodium Chloride (Rocksalt) structure
- Example: AgCl, CaO, MgO, KF, KCl, LiCl
Na+at corners: (8 ×1/8) = 1,
Na+at face centres (6 ×1/2) = 3
Cl–at edge centres (12 ×1/4) =3
Cl–at body centre = 1
Unit cell contents are 4(Na+) and4(Cl–)
Summary of FCC lattice
One crystallattice + different basis → different crystal structures!