Phase Transformation and Magnetic Properties in Ni_<52>Fe_xMn_<21-x>Ga_<27> Alloys
Effect of chemical composition was investigated on martensitic transformation temperatures, Curie temperature, magnetization for Ni<sub>52</sub>Fe<sub><i>x</i></sub>Mn<sub>21−<i>x</i></sub>Ga<sub>27</sub> alloys. X-ray diffraction patterns revealed that all the samples were in a single Heusler (L2<sub>1</sub>) phase state at room temperature. Forward and reverse martensitic transformation temperature, <i>M</i>* and <i>A</i>*, decreased with Fe content, <i>x</i>, up to 15 mol% and then turned to increase by further addition of Fe. Composition dependence of the Curie temperature exhibited a reversed tendency compared with <i>M</i>*. The structure of martensite was 10M for the alloys with <i>x</i><15 and a mixture of 14M and 10M for <i>x</i>=20. Electron diffraction patterns of L2<sub>1</sub> phase exhibited intense diffuse streaks on cooling, which were longer than those observed in ternary Ni–Mn–Ga.
- ISIJ international
ISIJ international 46(9), 1283-1286, 2006-09-15
The Iron and Steel Institute of Japan