A. Go

Electronic structure and magnetism of Fe3−xCrxSi alloys

Abstract The study of the electronic structure and magnetic properties of the Fe3−xCrxSi compound is motivated by the Mossbauer and neutron spectroscopy measurements showing unusual behaviour of Cr in such alloys. The site preferences of Cr in Fe3Si and the effect of local environment on formation of local magnetic moments are examined using self-consistent spin-polarised TB-LMTO method. The results of calculations essentially confirm the values and orientations of magnetic moments of iron and chromium atoms. However, they do not explain an experimental observation of almost equal occupation of A, B and C sites by chromium.

Electric and Magnetic Properties of bcc Fe Based Multicomponent Alloys

The electrical and magnetic properties of a bcc Fe 1- x A x , system with the average atom formed by A = (Al, Si, V, Cr) are presented. Compositions were chosen to obtain alloys of simple structure with control parameter ( x ) covering some important Heusler alloys. Systematic changes in the residual resistivity, magnetic moments, and electronic structure with concentration x are observed. The so-called parallel-resistivity formula ρ -1 =ρ ideal -1 +ρ sat -1 was used for quantitative characterization of the concentrated alloys, where ρ ideal denotes a contribution resulting from different mechanisms of scattering and ρ sat represents a shunt resistivity. At small concentrations x , the main contribution comes from structural disorder. It is shown that the density of states at the Fermi level is substantially reduced at larger x in agreement with results of electronic structure calculations.

An Influence of the Local Environment on Local Magnetic Moments and Hyperfine Fields in Fe3-xMnxAl

Ferromagnetic, intermetallic compound Fe3Al exhibits DO3-type crystal structure. There are two non-equivalent types of iron with different chemical neighbourhood – (A,C) and B sublattices. As a consequence of the different nearest environments of the iron atoms at these sites the different electronic and magnetic properties connected with these positions are observed. The aim of our research is to investigate the influence of the local surrounding of the iron on its magnetic moment and hyperfine field in compound Fe3-xMnxAl where iron is substituted by manganese.

Magnetic and structural properties of Fe3−xCrxAl0.5Si0.5

Results of X-ray, neutron, magnetization and M?ssbauer measurements on polycrystalline samples of Fe3?xCrxAl0.5Si0.5 (x = 0, 0.125, 0.250, 0.375 and 0.5) alloys are presented. The alloys crystallize in the structure of DO3 type, and their unit cell volumes are practically independent of the chromium concentration. X-ray and neutron diffraction confirmed the phase homogeneity of all the samples. Neutron and Mossbauer measurements disclosed that Cr atoms occupy preferentially B-sites, while D sites are almost entirely occupied by Al and Si. The total magnetisation as well as the site and individual magnetic moments ?Fe(A,C), ?Fe(B) and ?Cr(B,D) have been found to be linearly dependent on the chromium concentration.