K. Lawniczak-jablonska et al., The influence of Fe atom location on the electronic structure of Ni3Al1-xFex: LMTO calculation and x-ray spectroscopy, J PHYS-COND, 12(10), 2000, pp. 2333-2350
The electronic structure of Ni3Al1-xFex ordered alloys was calculated using
the ab initio self-consistent linear muffin-tin orbital method with the lo
cal density approximation. Two models of the preference in the site occupan
cy at the elemental cell were considered: (i) the Fe atoms substitute the A
l atoms located at the corners of the fee cube; (ii) the Fe atoms substitut
e the Ni atoms located at the faces of the cube and the appropriate number
of Ni atoms is located at the cube corners. Changes in the 'raw' density of
states distribution (DOS) for these two models were discussed and compared
with the x-ray spectra. The magnetic moments calculated for the first mode
l resemble the experimental data more than those calculated for the second
one. The DOS distributions were calculated over a wide energy range in the
valence as well as in the conduction band and projected on the constituent
atoms separately for different symmetries of states. Such an approach allow
ed us to compare predictions of the theory with the appropriate x-ray spect
ra. In all collected x-ray spectra, one can find changes of characteristic
features consistent with the changes observed in the calculated DOS under t
he assumption of the first model of site occupancy. The one-electron model
was utilized in the spectrum interpretation. The performed studies indicate
d that it is the first model of Fe substitution that finds confirmation in
the magnetic and x-ray investigations.