A semimetal is a material with very small overlap between bottom of conduction band and top of valence band. They have no band gap, but a negligible density of states at the Fermi level.
In a semimetal the bottom of the conduction band is typically situated in a different part of of the BZ than the top of the valence band.
Typical Semimetals
The classic semimetals are
- Arsenic (As)
- Antimony (Sb)
- Bismuth
- - Tin (gray tin)
- Graphite