The martensitic transformation and magnetic properties in Ni50−x Fe x Mn32Al18 ferromagnetic shape memory alloys

First Principles and Monte Carlo Calculations of Structural and Magnetic Properties of FexNi2-xMn1+yAl1-yHeusler Alloys

“…Further increase in Ni content leads to increase in MCE. Thus, the positive magnetic entropy change (ǻS § 3.35 J/kgK) in Ni 44 Fe 6 Mn 32 Al 18 under magnetic field change of 30 kOe has been found by Xuan et al [12]. Based upon the information, we can suggest that the families of Fe x Ni 2-x Mn 1+y Al 1-y compositions are the promising candidates in the development of multifunctional materials.…”

Effect of deposition temperature on the structure, magnetic and transport properties in Co2MnSi Heusler films

“…Curie temperature T C above room temperature (RT), high saturation magnetization, perpendicular magnetic anisotropy, shape-memory property and highly spin-polarized density of states at the Fermi level [6][7][8][9][10][11][12][13][14][15]. As a typical example, the full Heusler alloy Co 2 MnSi is thought to be an excellent candidate in spintronic applications due to several good features such as high conductivity, T C = 985 K, and theoretically predicted half-metal property with a large energy gap in the minority band of *0.4 eV [4,10,17].…”

Coupling Phenomena in Magnetocaloric Materials

“…Employingt he strong chemo-magnetic coupling in these alloys,i ti sacommon route to increaset he magnetization change duringM Ta nd hence the MCE by dopingt he system with as mall amount of Co or Fe. [15,42] Previous experimental measurements showed that due to the substitution of Co or Fe for Ni, the magnetizationo ft he high-temperature cubic austenite phase gets significantlye nhanced, whereas the changef or the low-temperature martensite phase is very minimal. [42,43] Using ab initio calculationsi th as been shown that the additiono fC oo rF ec hanges the magnetic state of the cubic austenite phase of Ni 50Àx M x Mn 37.5 Al 12.5 (M = Co or Fe).…”

“…[15,42] Previous experimental measurements showed that due to the substitution of Co or Fe for Ni, the magnetizationo ft he high-temperature cubic austenite phase gets significantlye nhanced, whereas the changef or the low-temperature martensite phase is very minimal. [42,43] Using ab initio calculationsi th as been shown that the additiono fC oo rF ec hanges the magnetic state of the cubic austenite phase of Ni 50Àx M x Mn 37.5 Al 12.5 (M = Co or Fe). [44] Fort he case of Ni 50 Mn 37.5 Al 12.5 the excessM na toms occupying the Al sub-lattice align in the opposited irection to the host Mn atoms,w hich is referred to as the AFM E state.T he substitution of Co or Fe howevera ligns all Mn spins irrespective of their occupationi nt he same direction and is referred to as the FM state.F igure 6s hows that the criticala mounto fC on eeded for the AFM E -to-FM transition is lower than that of Fe.T his indicates that Co induces ferromagnetism more strongly than Fe, which is also supported by the magnetice xchange parameters.I nN i 50 Mn 37.5 Al 12.5 , the Mn-Mn excess antiferromagnetic interaction is the largest, which stabilizes the system in the AFM E state (Figure 7a).…”