Title :
Magnetostrain and magnetization of the Ni-Mn-Ga single crystal
Author :
Jiang, Chengbao ; Wang, Jingmin ; Xu, Huibin
Author_Institution :
Dept. of Mater. Sci. & Eng., Beijing Univ. of Aeronaut. & Astronaut., China
Abstract :
6.2% and 5.8% giant magnetic field induced strains (MFIS) are achieved along two different orthogonal directions of a Ni50Mn27.5Ga22.5 single variant sample with a switching magnetic field of 2.4 kOe. A "magnetization jump" effect is observed along an initially hard direction at the switch field of the magnetostrain. A high saturation magnetization of 71.3 emu/g and magnetocrystalline anisotropy of 1.8 × 105 J/m3 are tested in the near single variant sample. The Zeeman energy is calculated to be 1.4 × 105 J/m3, close to the mechanical deformation energy of 1.2 × 105 J/m3, which is regarded as the driving force of the twin boundaries motion. The temperature dependence of the magnetostrain is also investigated in a wide temperature range from -194 K to 290 K. Furthermore, powder X-ray diffraction pattern of Ni50Mn27.5Ga22.5 demonstrates 5M tetragonal modulated martensite at room temperature.
Keywords :
X-ray diffraction; deformation; ferromagnetic materials; gallium alloys; magnetic anisotropy; magnetic transition temperature; magnetostriction; manganese alloys; martensitic structure; martensitic transformations; nickel alloys; twin boundaries; -194 to 290 K; 293 to 298 K; Ni50Mn27.5Ga22.5; Zeeman energy; giant magnetic field induced strains; magnetization jump; magnetocrystalline anisotropy; magnetostrain; mechanical deformation; powder X-ray diffraction; room temperature; saturation magnetization; switching magnetic field; tetragonal modulated martensite; twin boundaries motion; Anisotropic magnetoresistance; Magnetic anisotropy; Magnetic field induced strain; Magnetic switching; Perpendicular magnetic anisotropy; Saturation magnetization; Switches; Temperature dependence; Temperature distribution; Testing;
Conference_Titel :
Magnetics Conference, 2005. INTERMAG Asia 2005. Digests of the IEEE International
Print_ISBN :
0-7803-9009-1
DOI :
10.1109/INTMAG.2005.1464406