Fabrication and Characterization of Epitaxial Films of Superconductor NbN and Highly Spin-Polarized Heusler Alloy Co2Fe0.4Mn0.6Si

We report structural, magnetic, and transport properties of epitaxial films of superconductor NbN and highly spin-polarized Heusler alloy Co
₂
Fe
_0.4
Mn
_0.6
Si (CFMS). The saturation magnetization Ms of the film was 870 emu/cm
³
, which is slightly smaller than values reported earlier. With an increase of CFMS thickness dCFMS, the sheet resistance R
_sq
decreased and the upper critical field μ
₀
H
_c2
(0) decreased monotonically, while the superconducting transition temperature T
_c
exhibited a minimum around dCFMS = 3 nm. A theoretical analysis of superconducting fluctuations revealed that the high spin polarization of the CFMS layer affected the pair breaking parameter δ, the superconducting coherence length ξ(0), and the diffusion coefficient D.