Lattice parameters and Curie-point anomalies of iron-cobalt alloys

Lattice-parameter-temperature relationships have been examined for iron-cobalt solutions containing up to 12 wt.% cobalt for temperatures up to approximately 900°C, with particular attention being paid to the Curie-point regions. Cobalt additions progressively reduced the magnitude of the lattice-parameter anomaly previously reported for iron by Ridley and Stuart until at 12 wt.% cobalt no anomaly was observed. The results showed that volume changes resulting from the ferro-magnetic-paramagnetic transition had no significant effect on the room-temperature lattice parameters of iron-cobalt alloys, which show a marked deviation from Vegard's law.