- a solid solution of carbon or of carbon and other elements in gamma iron, having a face-centered cubic lattice at all temperatures.
- an allotrope of iron, stable between 910°C and 1400°C and having a face-centered cubic lattice; gamma iron.
- a solid solution of carbon in face-centred-cubic gamma iron, usually existing above 723°C
- the gamma phase of iron, stabilized at low temperatures by the addition of such elements as nickel
