Magnetic field dependence of electrical resistivity and thermopower in Ni50Mn37Sn13 ribbons
Maheswar Repaka, Durga Venkata
Ramanujan, Raju Vijayaraghavan
Date of Issue2015
School of Materials Science and Engineering
We report magnetization, magnetoresistance (MR) and magnetothermopower (MTEP) of melt spun Ni 50Mn37Sn13 ribbons which exhibit an austentite to martensite phase transition at a temperature (TM ) ≈ 294 K. Upon cooling from 400 K, dc-resistivity and thermopower show abrupt changes at TM , indicating a change in the electronic density of states. The thermopower is negative from 400 K down to 10 K. Application of a magnetic field of μ 0 H = 5 T decreases TM by 5 K and induces large negative MR (-23%) but positive MTEP (9%) near TM . While the MR is appreciable from TM down to 10 K, MTEP is significant only below 60 K (MR = -2.5% and MTEP = +300% at 10 K). The magnetic field dependence of resistivity and thermopower show either reversible or irreversible behavior near TM , depending on whether the sample is zero-field cooled or field-cooled, which indicates that the electronic band structure near TM is magnetic history dependent.
© 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi.org/10.1063/1.4930592]