Magnetic Properties of Melt-Spun CoMnSi(B) Alloys

MnCoSi and MnCoSiB0.5 alloys were obtained by melt-spinning technique in order to attain polycrystalline microstructures with average grain sizes well below 10 microns. Phase distribution studied by X-ray analysis indicated single-phase materials with orthorhombic structure and TiNiSi-type crystal symmetry. Chemical homogeneity was verified by means of scanning electron microscopy, whereas magnetic behavior corresponded to soft magnetic materials with coercivity values lower than 20 Oe and saturation magnetization of 80 emu/g. Magnetocaloric response of these MnCoSiB alloys was characterized by a maximum magnetic entropy change of 1.0 J/kg K (for a magnetic field variation of 2.0 Tesla) and attractive refrigerant capacity over 100 J/kg, which represents a significant enhancement respect to equivalent MnCoGe alloys.

Automated summary

MnCoSi and MnCoSiB0.5 alloys with polycrystalline microstructures were obtained using the melt-spinning technique. These alloys exhibited single-phase materials with orthorhombic structure and TiNiSi-type crystal symmetry, as determined by X-ray analysis. The alloys also showed soft magnetic behavior with coercivity values lower than 20 Oe and saturation magnetization of 80 emu/g. The MnCoSiB alloys had a maximum magnetic entropy change of 1.0 J/kg K and attractive refrigerant capacity over 100 J/kg, representing a significant improvement compared to equivalent MnCoGe alloys.