Martensitic Transformation and Magnetic Properties of Cu-Ga-Mn β Alloys

Abstract

The martensitic transformation and magnetic properties of Cu-Ga-Mn alloys were investigated. The alloys in the composition range Cu-21 at%Ga-(13-15)at%Mn were found to exhibit a thermoelastic martensitic transformation from an L2 1 parent to a 2H martensite in the ferromagnetic state. This martensitic transformation disappeared with the precipitation of the ! phase induced by aging at room temperature.

Influence of Co Addition on Martensitic and Magnetic Transitions in Ni-Fe-Ga β Based Shape Memory Alloys

“…From the SAD pattern, the crystal structure was identified as the tetragonal L1 0 (2 M) structure, although 14 M and/or 10 M modulated structures are more common to occur in the Ni-Fe-Ga ternary alloys annealed at the same temperature. 13,14) However, these modulated structures were also observed in the several NiFe-Co-Ga alloys aged at some temperatures lower than 450 C. Details of the effect of annealing temperature on the crystal structure of the Ni-Fe-Co-Ga alloys will be reported elsewhere. 24) …”

“…1) Since then, many ferromagnetic shape memory candidates have been investigated, such as Fe-Pd, 2) Fe-Pt 3) Ni-Mn-(Al, Sn, Sb, In), 4,5) Co-Ni-(Al, Ga), [6][7][8][9][10] Ni-Fe-(Al,Ga) [11][12][13] and Cu-Mn-Ga 14) alloy systems. The present authors proposed the Ni-Fe-Ga alloy system as promising ferromagnetic shape memory materials.…”

Characterization of new ferromagnetic Fe-Co-Zn-Ga alloys by ab initio investigations

“…Furthermore, Ni-Mn-Ga alloys are disadvantageous because of their poor room temperature ductility or high costs of elements [1][2][3]. In the literature, various other systems including Ni-Mn-(Al, Sn, Sb, In) [4,5], Co-Ni-(Al, Ga) [6][7][8][9][10][11][12][13], Ni-Fe-(Al, Ga) [14] and Cu-Mn-(Al, Ga) [15,16] have been proposed as candidates for new FSMAs. Of special interest are Heusler systems based on Co, Fe, and Zn: For the Co-Ni-(Al, Ga) and Ni-Ga-Fe-Co alloys, the martensitic start temperature T S decreases with increasing Co content while Curie temperature and spontaneous magnetization increase [17,18].…”

Effects of Aging and Co Addition on Martensitic and Magnetic Transitions in Ni–Al–Fe β-based Shape Memory Alloys

“…1) To date several candidates for ferromagnetic shape memory alloys (FSMAs), including Fe-Pd, 2) Fe-Pt 3) and Co-Ni-Ga 4,5) alloy systems, have been reported. The present authors have also conducted systematic studies on martensitic and magnetic transitions in several ordered bcc alloy systems and found Ni-Mn-Al, 6) Co-Ni-Al, 7) Co-Ni-Ga, 5) Ni-Fe-Ga, 8,9) Cu-Mn-Ga 10) and Ni-Mn-(In, Sn, Sb) 11,12) to be promising ferromagnetic shape memory alloy systems.…”