Observation of Griffiths-like phase in the quaternary Heusler compound NiFeTiSn

TL;DR

This study reports the discovery of a Griffiths-like phase in the semiconducting quaternary Heusler compound NiFeTiSn, revealing complex magnetic behavior linked to structural disorder and antisite defects.

Contribution

First observation of a Griffiths-like phase in a semiconducting 3d transition metal-based intermetallic with antiferromagnetic ground state.

Findings

NiFeTiSn exhibits a Griffiths-like phase with ferromagnetic clusters.

Antisite disorder between Fe and Ti likely causes the Griffiths-like behavior.

Unusual temperature dependence of resistivity linked to structural disorder.

Abstract

The quaternary Heusler compound NiFeTiSn can be considered to be derived from the exotic pseudogap-compound Fe2TiSn by the replacement of one Fe atom by Ni. In contrast to Fe2TiSn, which shows a disorder-induced ferromagnetic phase, the ground state of NiFeTiSn is antiferromagnetic with the signature of spin canting. Interestingly, NiFeTiSn shows a Griffiths-like phase characterized by isolated ferromagnetic clusters before attaining the antiferromagnetic state. The Griffiths-like phase is possibly associated with the antisite disorder between Fe and Ti sites as evident from our powder X-ray diffraction study. The compound also shows rather an unusual temperature dependence of resistivity, which can be accounted for by the prevailing structural disorder in the system. NiFeTiSn turned out to be a rare example where a Griffiths-like phase is observed in a semiconducting 3d transition metal-based intermetallic compound with an antiferromagnetic ground state.