Investigation of the quaternary Fe2− xCoxMnSi (0 ≤x≤ 0.6) alloys by structural, magnetic, resistivity and spin polarization measurements (original) (raw)

Detailed study of the Fe 2-x Co x MnSi (0 ≤ x ≤ 0.6) alloys has been carried out by investigating the samples with x-ray diffraction, Mössbauer spectroscopy, magnetization, transport and current spin polarization measurements. A perfectly ordered L2 1 phase is found to exist for x = 0.4. Competing magnetic interactions between ferromagnetic (FM) and antiferromagnetic (AFM) phases are found to exist in Fe 2-x Co x MnSi for x < 0.2 whereas the AFM phase completely disappears for x ≥ 0.2 as revealed by the magnetization and resistivity data. Anomalous, semiconducting-like behaviour is observed for x = 0.4. Current spin polarization has been estimated from different conductance curves obtained by using the point contact Andreev reflection technique. Alloys with x=0.2 and 0.4 show spin polarization values of 0.61±0.1 and 0.66 ± 0.1 respectively.