Invar properties in Fe-Ni system from band theory

✍ Scribed by E.G. Moroni; T. Jarlborg

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 433 KB
• Volume: 161
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(89)90115-4

✦ Synopsis

The band structures of ordered fee Fe-Ni compounds of different compositions have been calculated using the self-consistent LMTO band method in the local spin density approximation.

The results include total energy, pressure, bulk modulus, magnetic moments, etc. and their variation with volume. At zero temperature we find that the total energy separation between the ferromagnetic (FM) and non-magnetic (NM) state is very small near the invar composition.

In the Fe-rich region we find that the Fe-moments have a strong variation with volume. Free energy calculations including lattice and electronic contributions are used to study invar properties at higher temperatures.

From simple two level models we obtain qualitatively invar behaviour.

The calculated results are compared with other calculations and with various experimental results.