Magnetochemical origin for Invar anomalies in iron-nickel alloys
UNSPECIFIED. (2002) Magnetochemical origin for Invar anomalies in iron-nickel alloys. PHYSICAL REVIEW B, 66 (1). -. ISSN 1098-0121Full text not available from this repository.
Official URL: http://dx.doi.org/10.1103/PhysRevB.66.014416
Zero- and finite-temperature (T) first-principles calculations versus composition (c) show that magnetochemical effects lead to Invar anomalies in Fe-(Ni, Co, Pt) alloys. Chemical short- or long-range order and negative interatomic exchange interaction of electrons in antibonding majority-spin states force the face-centered-cubic lattice to compete simultaneously for a smaller volume (from antiferromagnetic tendencies) and a larger volume (from Stoner ferromagnetic tendencies). The resulting additional negative lattice anharmonicity is very large for Fe-(Ni, Co) while absent for Fe-Pt. Our results explain the T- and c-dependent behavior of Invar properties, including the lattice softening and thermal expansion of Fe-Ni. In addition, the occurrence of a noncollinear spin structure at T=0 K near Invar can be understood on the basis of our results.
|Item Type:||Journal Article|
|Subjects:||Q Science > QC Physics|
|Journal or Publication Title:||PHYSICAL REVIEW B|
|Publisher:||AMERICAN PHYSICAL SOC|
|Date:||1 July 2002|
|Number of Pages:||8|
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