PY3090Preparation of MaterialsLecture 2
Colm Stephens
School of Physics
Face CentredCubic (FCC)• e.g. -Fe,
Al, Ni, Cu,Ag, Pt, Au
Hexagonal Close Packed (HCP)• e.g. Be, Mg, -Ti, Zn, Zr
HCP Unit cell – plan view 1st layer
ratrat
HCP Unit cell – plan view 2nd layer
ratrat
HCP Unit cell – side view 2 layers
rat
C/2
Close Packing FCC vs. HCP
Cristobolite FCC• e.g. SiO2
Zinc blende(FCC)• e.g. GaAs,
AlP, InSb(III-V SCs)ZnS, CdS,HgTe(II-VI SCs)
Carbon polymorphism• Graphite
Carbon polymorphism• Buckminster
Fullerene C60
• Carbon nanotube
Imperfections• Point defects
Notice lattice strains• Point defects