[Zurück]

J. Cieslak, J. Tobola, M. Reissner:
"Magnetic properties of sigma-phase FeCrX (X=Co, Ni) alloys: Experimental and theoretical study";
Acta Materialia, 123 (2017), S. 35 - 43.

Experimental (vibrating sample magnetometry) and theoretical (electronic structure calculations using self-consistent Korringa-Kohn-Rostoker Green's function method, also including the coherent potential approximation) studies were performed on a series of intermetallic s-phase FeCrX (X ¼ Ni, Co) compounds in systematic way. In s-FeCrNi (Ni concentration is limited to ~ 10 at%) a slight enhancement of magnetic properties when replacing Fe with Ni atoms and a slight attenuation of these properties when replacing Fe with Cr was experimentally observed. In the case of s-FeCrCo, the reason for disappearance of magnetic properties was explained, since the substitution of Fe with Co leads to systematic attenuation of TC and m. Consequently, s-CoCr was established to be non-magnetic from accurate measurements of magnetisation for series of s-FexCrCo samples with x tending to zero. The decrease of average magnetic moment in s-FeCrCo well corroborates with the results of electronic structure calculations assuming different models for chemical disorder. In order to enlighten reasons for magnetism onset in s-FeCrX, the KKR-CPA spin-polarised density of states and magnetic moments of Fe impurities diluted on all sublattices were computed in s-CoCr and hypothetical s-NiCr. In both cases, the largest Fe magnetic moment was calculated on B (~2mB) and next C (~1.3mB and D (~0.5mB) sites, while almost vanishing values were found on A and E sites.

http://dx.doi.org/10.1016/j.actamat.2016.10.010