Ferromagnetism in carbon-doped Mn5Si3 films

Abstract

The effect of carbon doping on the structural and magnetic properties of Mn5Si3Cx films is investigated for different substrate temperatures TS and concentrations x. Samples with x≈0.75 prepared at TS=650–750 K exhibit ferromagnetic order with enhanced ordering temperatures TC well above room temperature in contrast to the undoped antiferromagnetic Mn5Si3 compound. Structural analysis shows that C is incorporated interstitially in the hexagonal Mn5Si3-type structure with a lattice expansion with respect to the undoped compound. The enhanced ferromagnetic order is presumably not simply due to a change of the interatomic Mn–Mn distances but due to a change of the electronic structure and/or exchange interactions.

Ferromagnetism in Mn/X/Si (X = B, BN, B4C, SiC) trilayers

“…Therefore, it is plausible that the Mn/X/Si trilayers include other ferromagnetic compounds that have high Curie temperatures. It is also reported that the carbondoping changes the Mn 5 Si 3 compound from antiferromagnetic to ferromagnetic and the Curie temperature of the Mn 5 Si 3 C 0.75 compound is 350 K [9]. Therefore, it is likely that the Mn/SiC/Si and the Mn/B 4 C/Si trilayers in this study include the Mn 5 Si 3 C 0.75 compounds.…”

“…(2) Annealing produces unknown ferromagnetic compounds near the Mn layers. In the Mn -Si systems, Mn 3 Si and Mn 5 Si 3 are antiferromagnetic materials [8,9]. Only the MnSi is ferromagnetic, whose Curie temperature and magnetic moment are around 40 K and 0.4 m B /Mnatom, respectively [10,11].…”

Preparation and structural characterization of ferromagneticMn5Si3CSürgers1, Gajdzik2, Fischer3 et al. 2003Phys. Rev. BSelf Cite320250View full textAdd to dashboardCite

“…7,8 The Curie temperature was determined from an extrapolation of the magnetization M (T) to M (T C )ϭ0 measured in a weak magnetic field of 5 mT.…”

“…In this respect it is remarkable that the saturation of carbon uptake in Mn 5 Si 3 C x can be enhanced up to xϷ1 by magnetron sputtering of films from elemental targets. 7 The magnetic properties of these films have been investigated previously by the magneto-optic Kerr effect and magnetometry. 7,8 A maximum T C ϭ350 K was obtained for a substrate temperature T S ϭ470°C.…”

“…7 The magnetic properties of these films have been investigated previously by the magneto-optic Kerr effect and magnetometry. 7,8 A maximum T C ϭ350 K was obtained for a substrate temperature T S ϭ470°C. The enhancement of T C by carbon doping was also demonstrated for isostructural Mn 5 Ge 3 films.…”