Giant Positive Magnetoresistance and field-induced metal insulator transition in Cr2NiGa

TL;DR

This study investigates the magneto-transport properties of the new Heusler compound Cr2NiGa, revealing giant positive magnetoresistance and a field-induced transition from metallic to insulating behavior at low temperatures.

Contribution

The paper reports the synthesis and detailed magneto-transport analysis of Cr2NiGa, demonstrating unprecedented magnetoresistance and a novel field-induced metal-insulator transition.

Findings

Magnetoresistance up to 112% at 150 kOe

Field-induced metal-insulator transition below 50 K

Applicability of multi-band transport model

Abstract

We report here the magneto-transport properties of the newly synthesized Heusler compound Cr2NiGa which crystallizes in a disordered cubic B2 structure belonging to Pm-3m space group. The sample is found to be paramagnetic down to 2 K with metallic character. On application of magnetic field, a significantly large increase in resistivity is observed which corresponds to magnetoresistance as high as 112% at 150 kOe of field at the lowest temperature. Most remarkably, the sample shows negative temperature coefficient of resistivity below about 50 K under the application of field gretare than or equal to 80 kOe, signifying a field-induced metal to `insulating' transition. The observed magnetoresistance follows Kohler's rule below 20 K indicating the validity of the semiclassical model of electronic transport in metal with a single relaxation time. A multi-band model for electronic transport, originally proposed for semimetals, is found to be appropriate to describe the magneto-transport behavior of the sample.