Magnetic and thermal properties of Ni–Mn–Ga shape memory alloy with Martensitic transition near room temperature

Magneto-Structural Properties of Ni2MnGa Ferromagnetic Shape Memory Alloy in Magnetic Fields

“…The sequential phenomenon is observed in single crystal Ni 2.19 Mn 0.81 Ga [21]. Zhu et al [11] suggest that the small satellite peaks in heat flow plot of Ni 51.9 Mn 23.2 Ga 24.9 , which flanks the central peak, indicate that the structural transition takes place in multiple steps. The results of thermal strain in a magnetic field and magnetic field-induced strain yield information about the twin boundary motion in the fields.…”

“…Several studies on Ni-Mn-Ga alloys have addressed martensite transformation and correlation between magnetism and crystallographic structures [6][7][8][9][10][11][12][13][14][15][16][17][18]. Ma et al [7] studied the crystallography of Ni 50+x Mn 25 Ga 25-x alloys (x = 2-11) by powder X-ray diffraction and optical microspectroscopy.…”

“…The magnetization results indicate that the martensite Ni-Mn-Ga alloys have higher magnetocrystalline anisotropy compared to Mn ferrites. Furthermore, magnetization results indicate that the coercivity and saturation field at the martensite phase are higher than those of the cubic austenite phase [11][12][13][14][15]. Zhu et al [11] investigated the lattice constant change Δc/c of −4.8% of Ni 51.9 Mn 23.2 Ga 24.9 by means of X-ray diffraction study around martensite transformation temperature.…”

“…Furthermore, magnetization results indicate that the coercivity and saturation field at the martensite phase are higher than those of the cubic austenite phase [11][12][13][14][15]. Zhu et al [11] investigated the lattice constant change Δc/c of −4.8% of Ni 51.9 Mn 23.2 Ga 24.9 by means of X-ray diffraction study around martensite transformation temperature. Chernenko et al [12] also studied about magnetization and X-ray powder diffractions, and clear changes were found at T M for both measurements.…”

Thermal Strain and Magnetization Studies of the Ferromagnetic Heusler Shape Memory Alloys Ni2MnGa and the Effect of Selective Substitution in 3d Elements on the Structural and Magnetic Phase

“…Several studies on Ni-Mn-Ga alloys address the martensite transition and correlation between magnetism and crystallographic structures [6][7][8][9][10][11][12][13][14][15][16][17][18]. Ma et al studied the crystallography of Ni50+xMn25Ga25-x alloys (x = 2-11) by powder X-ray diffraction and optical microspectroscopy [7].…”