Title :
In-situ Lorentz TEM cooling study of magnetic domain configurations in Ni2MnGa
Author :
De Graef, Marc ; Willard, Matthew A. ; McHenry, Michael E. ; Zhu, Yimei
Author_Institution :
Dept. of Mater. Sci. & Eng., Carnegie Mellon Univ., Pittsburgh, PA, USA
fDate :
7/1/2001 12:00:00 AM
Abstract :
Magnetic domain configurations in the ferromagnetic shape memory alloy Ni2MnGa are analyzed by means of Lorentz microscopy and noninterferometric phase reconstruction methods. Domain structures in the cubic phase consist of cross-tie walls in the thinnest portions of the foil, and more complex configurations in thicker regions. At low temperature, the magnetization configurations change as the structure transforms martensitically to a tetragonal phase. A simple model for the magnetization changes is proposed
Keywords :
ferromagnetic materials; gallium alloys; magnetic domains; magnetisation; manganese alloys; martensitic transformations; nickel alloys; shape memory effects; transmission electron microscopy; Lorentz microscopy; Ni2MnGa; Ni2MnGa foil; cross-tie wall; cubic phase; ferromagnetic shape memory alloy; in-situ TEM cooling; magnetic domain structure; magnetization; martensitic transformation; noninterferometric phase reconstruction; tetragonal phase; Cooling; Magnetic analysis; Magnetic domain walls; Magnetic domains; Magnetic force microscopy; Magnetization; Reconstruction algorithms; Shape memory alloys; Temperature; Transmission electron microscopy;
Journal_Title :
Magnetics, IEEE Transactions on
