CH1012
L1 /
‹#›
L1 /
6
NETWORK SOLIDS I
Network solids directional covalent
bonds “NO - MOLECULE”. Properties
atypical: high mp., bp., brittle.
bonds “NO - MOLECULE”. Properties
atypical: high mp., bp., brittle.
Diamond = hardest natural
substance, colourless, insulator. mp 4100oC
substance, colourless, insulator. mp 4100oC
Bonding : perfect tetrahedral, single bonds.
Graphite = slippery, conductor.
R = 3.41Ĺ
Layers of fused hexagonal carbon rings
- layers held
close by weak dispersion
forces
- the interlayer space p e-s conduct well
Graphite (r 2.2
g/cm3) ® diamond (r 3.5
g/cm3)
requires 150 000 Atm and 2800oC. or
requires 150 000 Atm and 2800oC. or
Chemical Vapour Deposition (CVD)
methane, 600oC, 0.001 atm ® diamond
surface deposition at 100mm /h.
methane, 600oC, 0.001 atm ® diamond
surface deposition at 100mm /h.
