In-situ observations of magnetic domain wall motion in a Ni80-Fe20 thin film electroplated on a Cu film were performed by Lorentz TEM. Detailed magnetization distribution was investigated by differential phase contrast
microscopy. The magnetic properties of the coercivity and saturation magnetic flux density were measured to be 6.5 Oe and 1.56 T, respectively. The diffraction ring pattern showed the Ni₃Fe FCC structure with
nanocrystalline nature (grain size 29 nm) and texture indicating the preferential orientation. We measured the domain width of 1.9 μm and found the fluctuation of magnetization direction coupled with two vortices. With
the in-plane and out-of-plane magnetic fields applied, domain wall motions were in-situ observed and discussed.