Bulk Spin Polarization ofCo(1−x)FexS2

Abstract

We report on a new method to determine the degree of bulk spin polarization in single crystal Co (1−x) FexS2 by modeling magnetic Compton scattering with ab initio calculations. Spin-dependent Compton profiles were measured for CoS2 and Co0.9Fe0.1S2. The ab initio calculations were then refined by rigidly shifting the bands to provide the best fit between the calculated and experimental directional profiles for each sample. The bulk spin polarizations, P , corresponding to the spinpolarized density of states at the Fermi level, were then extracted from the refined calculations. The values were found to be P = −72 ± 6% and P = 18 ± 7% for CoS2 and Co0.9Fe0.1S2 respectively. Furthermore, determinations of P weighted by the Fermi velocity (vF or v 2 F ) were obtained, permitting a rigorous comparison with other experimental data and highlighting the experimental dependence of P on vF .

Weyl fermions, Fermi arcs, and minority-spin carriers in ferromagnetic CoS 2

“…1 (A and B)] conclude that CoS 2 hosts a minority-spin electron pocket at the R point that leads to a peak in the minority-spin density of states (DOS), which would make CoS 2 a minority-spin conductor. This scenario is supported by magnetotransport experiments that suggest a sign flip in the spin polarization upon hole doping with iron that may turn CoS 2 into a half-metal (i.e., vanishing minority-spin DOS at E F ) due to the depopulation of a minority-spin electron pocket (16)(17)(18)(19)(20). On the other hand, calculations based on the generalized gradient approximation (GGA) (15,21) [see Fig.…”

Ferromagnetic ordering and half-metallic state of Sn2Co3S2with the shandite-type structure

“…The reliable experimental determination of the conduction electron spin polarization is a challenging task. [13][14][15] From a classification given in a review by Coey 13 Sn 2 Co 3 S 2 can be assigned to type I A half-metallic ferromagnets.…”

Calculating electron momentum densities and Compton profiles using the linear tetrahedron method

“…Magnetic Compton scattering [18] measures the projec-tion of the spin-resolved momentum density. Here components arising from spin-paired electrons cancel, allowing the spin magnetic moment [5], and spin polarisation to be determined [19]. Compton profiles (CPs), J(p z ), and magnetic Compton profiles (MCPs), J mag (p z ) are defined as…”