1. Variation of magnetoresistance in Ni2+xMn1-xGa with composition.
- Author
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Banik, S., Singh, Sanjay, Rawat, R., Mukhopadhyay, P. K., Ahuja, B. L., Awasthi, A. M., Barman, S. R., and Sampathkumaran, E. V.
- Subjects
PHYSICS research ,FERROMAGNETISM ,FERROMAGNETIC materials ,MAGNETIC fields ,FIELD theory (Physics) ,ELECTROMAGNETIC fields - Abstract
The magnetoresistance (MR) of Ni
2+x Mn1-x Ga (-1≤x≤0.35) ferromagnetic shape memory alloy shows a large increase in magnitude at room temperature (RT) with increasing x. For Mn2 NiGa (x=-1), MR at 8 T is -0.2%, while for Ni2.35 Mn0.65 Ga (x=0.35), it is -7.3%. Thus, MR of Ni2+x Mn1-x Ga can be varied over one order of magnitude by changing composition (x). Considering that the Curie temperature (TC ) varies with x, the MR behavior in the austenitic phase is explained on the basis of the s-d scattering model. By fitting the MR at 8 T in the austenitic phase for different x and T, a (T/TC )6 power law dependence is obtained. In contrast to the monotonic MR variation with x, the magnetization at RT is highest for Ni2 MnGa (x=0) and decreases for both Ni and Mn excess compositions. [ABSTRACT FROM AUTHOR]- Published
- 2009
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