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

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.