Nanoscale physics
Electric transport properties of a Ni-Mn-In alloy subjected to external stimuli
Konoplyuk S.M.1, Kolomiets A.V.2
1 Institute of magnetism of NASU and MESU, Vernadsky blvd. 36-b, Kyiv-03142, Ukraine. 
E-mail: ksm@imag.kiev.ua
2 Department of Physics, Lviv Polytechnic National University, St. Bandery str. 12, Lviv, Ukraine.

The polycrystalline Ni45.4Mn40In14.6 Heusler alloy was studied to find dominant factors affecting its electric transport behavior in austenitic and martensitic phases. Analysis of three main contributions into temperature dependent resistivity has shown that prevalent mechanisms of carrier scattering in the austenitic phase are scattering on structural and magnetic disorders rather than on thermal fluctuations. In spite of the small transformation volume effect of 0.09 %, application of hydrostatic pressure of 2 GPa results in almost threefold rise in the longitudinal resistivity and twofold rise in the Hall resistivity due to the pressure-induced martensitic transformation. The measurements of the ordinary Hall resistivity have shown that main charge carriers in both phases are holes whose mobility is ten times as high in the austenitic phase as in the martensitic one. The anomalous Hall resistivity (AHE) of the Ni45.4Mn40In14.6 reaches significant magnitude of 20 µΩ·cm in the martensitic phase. Unusual scaling relation between AHE and the longitudinal resistivity is discussed.