CS-08 Phase Transitions and Magnetic Properties of Cu and Fe Doped Ni2Mn0.55Cu0.35Fe0.10Ga Heusler Alloy
Creators: Hauwa Adedo
Jemma R. DeFeo
Venkateswara Yenugonda
Sumaiya Rahman
Arjun K. Pathak
and  Mahmud Khan
Publisher: name: IEEE
Year: 2025

The Ni2MnGa based Heusler alloys are extensively studied for the numerous multifunctional properties they exhibit. Many of these properties, like magnetocaloric effect, are associated with the first order martensitic phase transition that can be precisely controlled by varying the stoichiometry and by atomic doping [1, 2]. Upon heating, a first order coupled magnetostructural phase transformation is observed near 345 K in Ni2Mn0.70Cu0.30Ga, a Cu-doped derivative of the Heusler alloy Ni2MnGa [3]. A partial decoupling of the phase transitions occurs during cooling resulting in a large variation in the magnetocaloric properties of the material when the measurements are done while heating and cooling [3]. Here, we present a study on the phase transitions and associated magnetic properties of Ni2Mn0.55Cu0.35Fe0.10Ga, a Fe doped derivative of Ni2Mn0.70Cu0.30Ga. X-ray diffraction data showed a tetragonal structure at room temperature. The temperature dependence of magnetization data obtained while heating revealed two distinct transitions at 338 K and 368 K. On cooling the transitions were observed at 333 K and 355 K. The lower temperature transition showed a thermal hysteresis of ~5 K while the higher temperature transition exhibited a thermal hysteresis of ~13 K. The magnetic entropy changes obtained from isothermal magnetization data indicated that transition at 338 K is a second order transition while the one at 368 K is a first order phase transition. Peak entropy changes of -8 J kg-1 K-1 have been observed. The experimental data suggested that the martensitic phase transition occurred in a paramagnetic state in Ni2Mn0.55Cu0.35Fe0.10Ga. The work at State University of New York (SUNY), Buffalo State University, was supported by the National Science Foundation Award No. DMR-2213412.References: [1] M. Khan, I. Dubenko, S. Stadler and N. Ali, J. Phys. 97, 10M304 (2005). [2] S. Stadler, M. Khan, J. Mitchell, and N. Ali, Appl. Phys. Lett. 88, 192511 (2006). [3] S. A. Agbo, S. Bhatt, and M. Khan, Intermetallics 138, 107322 (2021).
The Ni2MnGa based Heusler alloys are extensively studied for the numerous multifunctional properties they exhibit. Many of these properties, like magnetocaloric effect, are associated with the first order martensitic phase transition that can be precisely controlled by varying the stoichiometry and by atomic doping [1, 2]. Upon heating, a first order coupled magnetostructural phase transformation is observed near 345 K in Ni2Mn0.70Cu0.30Ga, a Cu-doped derivative of the Heusler alloy Ni2MnGa [3]. A partial decoupling of the phase transitions occurs during cooling resulting in a large variation in the magnetocaloric properties of the material when the measurements are done while heating and cooling [3]. Here, we present a study on the phase transitions and associated magnetic properties of Ni2Mn0.55Cu0.35Fe0.10Ga, a Fe doped derivative of Ni2Mn0.70Cu0.30Ga. X-ray diffraction data showed a tetragonal structure at room temperature. The temperature dependence of magnetization data obtained while heating revealed two distinct transitions at 338 K and 368 K. On cooling the transitions were observed at 333 K and 355 K. The lower temperature transition showed a thermal hysteresis of ~5 K while the higher temperature transition exhibited a thermal hysteresis of ~13 K. The magnetic entropy changes obtained from isothermal magnetization data indicated that transition at 338 K is a second order transition while the one at 368 K is a first order phase transition. Peak entropy changes of -8 J kg-1 K-1 have been observed. The experimental data suggested that the martensitic phase transition occurred in a paramagnetic state in Ni2Mn0.55Cu0.35Fe0.10Ga. The work at State University of New York (SUNY), Buffalo State University, was supported by the National Science Foundation Award No. DMR-2213412.References: [1] M. Khan, I. Dubenko, S. Stadler and N. Ali, J. Phys. 97, 10M304 (2005). [2] S. Stadler, M. Khan, J. Mitchell, and N. Ali, Appl. Phys. Lett. 88, 192511 (2006). [3] S. A. Agbo, S. Bhatt, and M. Khan, Intermetallics 138, 107322 (2021).