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

The quaternary Heusler compound NiFeTiSn can be considered to be derived from the exotic pseudogap-compound Fe 2 TiSn by the replacement of one Fe atom by Ni. In contrast to Fe 2 TiSn, 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 unusual temperature dependence of resistivity, which can be accounted by the prevailing structural disorder in the system. NiFeTiSn turned out to be a rare example where Griffiths-like phase is observed in a semiconducting 3 d transition metal based intermetallic compound with antiferromagnetic ground state.