Abstract
X-ray powder diffraction, permeability, magnetization and differential scanning calorimetry measurements were carried out on the magnetic shape memory alloys Ni2MnGa1-xCux (0 ≤ × ≤ 0.25). On the basis of the experimental results, the phase diagram in the temperature-concentration plane was determined for this alloy system. The determined phase diagram is spanned by the paramagnetic austenite phase (Para-A), paramagnetic martensite phase (Para-M), ferromagnetic austenite phase (Ferro-A), ferromagnetic martensite phase (Ferro-M) and the premartensite phase. It was found that the magnetostructural transition between the phases Para-A and Ferro-M can occur in the concentration region 0.12 < × ≤ 0.14 and that Ni2MnGa1-xCux has the characteristics of the phase diagram similar to those of the phase diagrams of Ni 2+xMn1-xGa and Ni2Mn1-xCu xGa. In order to understand the phase diagram, the phenomenological free energy as a function of the martensitic distortion and magnetization was constructed and analyzed.
Original language | English |
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Pages (from-to) | 165-176 |
Number of pages | 12 |
Journal | Materials Science Forum |
Volume | 684 |
DOIs | |
Publication status | Published - 2011 May 17 |
Keywords
- Heusler alloy
- Phase diagram
- Phase transition
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering