Electron momentum density in Ni75Cu25 and Ni75Co25 disordered alloys: a high-resolution Compton-scattering study.

J. Kwiatkowska (1) , L. Dobrzynski (2, 3) , A. Andrejczuk (2) , E. Zukowski (2) , Ch Bellin (4) , G. Loupias (4) , A. Shukla (4, 5) , Th Buslaps (5)

1 Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences
2 Institute of Experimental Physics, University of Bialystok
3 The Soltan Institute for Nuclear Studies
4 IMPMC - Institut de minéralogie et de physique des milieux condensés
5 ESRF - European Synchrotron Radiation Facility

We report high-resolution Compton profiles (CPs) of Ni75Cu25 and Ni75Co25 disordered, ferromagnetic alloys measured along [100], [110] and [111] crystallographic directions. The directional CP anisotropies, profile derivatives and reciprocal form factors B(z) are analysed in detail and compared with first-principles KKR-CPA (Korringa–Kohn–Rostoker coherent potential approximation) calculations. Good overall agreement is found between the experimental and theoretical anisotropies. It follows from experiment that the majority-spin Fermi surface of the Ni75Cu25 and Ni75Co25 alloys occurs at higher momentum than the theory predicts. Also, a splitting in the secondary maxima in experimental B(z) functions of the alloys is observed, which is not predicted by the KKR-CPA calculations.

Mots clés: FERMI-SURFACE; PROFILE; NICKEL; AL; ANISOTROPY; LI

J. Kwiatkowska, L. Dobrzynski, A. Andrejczuk, E. Zukowski, Ch Bellin, et al.. Electron momentum density in Ni75Cu25 and Ni75Co25 disordered alloys: a high-resolution Compton-scattering study.. Journal of Physics: Condensed Matter, 2005, 17, pp.6425-6434. ⟨10.1088/0953-8984/17/41/013⟩. ⟨hal-00020284⟩