Structural and magnetic properties of Mn50Fe50−xSnx (x=10, 15 and 20) alloys

• Mn50Fe50-xSnx alloys were studied over a limited concentration range.
• Lower Sn alloys behaved similar to ß-Mn alloys both structurally and magnetically.
• Higher Sn alloys showed magnetic transitions similar to Mn3Sn and Fe3Sn.
• Resistivity showed bad metallic behavior with negetive temperature coefficient.

In this work we report measurements and comparisons of the structural, magnetic and transport properties of a series of Mn50Fe50−xSnx alloys (x=10, 15 and 20). We found that while the lower Sn composition sample stabilized in β-Mn-type crystallographic phase, the higher Sn composition alloys contained both β-Mn-type as well as Mn3Sn-type hexagonal DO19 phases. Through d.c. and a.c. magnetic property measurements we have established the existence of a ferromagnetic transition near room temperature followed by a spin reorientation at lower temperature in the Mn3Sn-type crystallographic phase of the alloys. Our resistivity study also revealed an interesting behavior with negative temperature coefficient (TCR) in these alloys.