Half-metallic Ni2MnSn Heusler alloy prepared by rapid quenching

• Rapid quenching method was employed to produce half-metallic Ni2MnSn Heusler alloy.
• Single crystalline L21 phase with well-defined anisotropy direction was obtained.
• Ni2MnSn prepared by rapid quenching method exhibit high spin polarization up to 70%.

We have employed melt-spinning method to produce Ni2MnSn-based half-metallic Heusler alloy. It allows fast and simple production of large amount of materials in a single production step avoiding high temperature post-production annealing. Microstructural, magnetic and spin polarization study of Ni2MnSn ribbon is used for characterization. SEM analysis reveals the polycrystalline structure with the columnar crystals grown perpendicularly to the ribbon plane. A single-phase austenite with L21 structure was confirmed by X-ray. Magnetic measurements shows the ordinary ferromagnetic behavior with Curie temperature 344 K and magnetic moment 4.08 µB/f.u. Particular crystal structure leads to the well defined anisotropy having an easy plane in the ribbon's plane. Finally, the spin polarization parameter P0 estimated by Point-Contact Andreev-reflection Spectroscopy is varying in the range 40–70% for Ni2MnSn which is comparable with other values reported earlier for other Heusler alloys.