Transport properties of Heusler compounds Fe3-xMnxSi (x = 1.6, 1.7 and 1.8) under magnetic fields

Ryota Kato,Ryutaro Ooka,Masahiko Hiroi,Iduru Shigeta,Tomohito Nonoyama

doi:10.1063/1.5043075

Abstract

Measurements of the electrical resistivity, magnetoresistance (MR), and Hall effects are performed to investigate the transport properties of Fe3-xMnxSi (x = 1.6, 1.7, and 1.8) under magnetic fields. It is known that Fe2MnSi exhibits a ferromagnetic transition at TC and an antiferromagnetic transition at a lower temperature (TA) to the phase referred to as the AF phase. A recent study on Fe1.3Mn1.7Si found another antiferromagnetic transition at a temperature below TA, defined as TA2, to a phase referred to as the AF2 phase. In this study, in MR measurements for x = 1.7 and 1.8, the change in MR with magnetic field is found to transition from positive to negative at certain magnetic fields. Comparing these results with those of magnetization measurements, these points correspond to the AF2-AF transitions. The results also indicate that these transitions occur at a higher field for x = 1.8 than for x = 1.7. The Hall effect measurements show the anomalous Hall effect for x = 1.6 and 1.7 in the temperature region where spontaneous magnetization is present, but not for x = 1.8, for which the ferromagnetic state appears to be absent. These results are consistent with the magnetization measurements.

Highlights

Heusler compounds are intermetallic compounds with the formula X2YZ, where X and Y are transition elements, and Z is an sp element.[1]
The AF2 phase and the AF2-AF transition have yet to be studied by resistivity measurements; this study investigates the properties of the AF and AF2 phases and the AF2-AF transition using measurements of the electrical resistivity, magnetoresistance (MR), and Hall effect for Fe3-xMnxSi with x = 1.6, 1.7, and 1.8
Measurements of the electrical resistivity, MR, and Hall effect were performed on Fe3-xMnxSi samples with x = 1.6, 1.7 and 1.8

Summary

Introduction

Heusler compounds are intermetallic compounds with the formula X2YZ, where X and Y are transition elements, and Z is an sp element.[1]. The transition temperatures at zero field, estimated from M(T ), are T C ∼ 85 K, T A ∼ 68 K, and T A2 ∼ 60 K for x = 1.76 The transition temperature T A2 depends on magnetic field, B, whereas T A does not depend strongly on B.6,9 for x = 1.6, T C and T A are ∼ 117 K and ∼ 66 K, respectively, whereas T A2 is not found as for x ≤ 1,5.10,11 Note that T C decreases as x increase but T A is almost constant,[5] leading to T C appearing to coincide with T A at around x = 1.7, the properties in this x region have been little studied.

Results

Conclusion