Lorentz microscopy observations of a nanocrystalline Fe44Co44Zr7B4Cu1 alloy

Domain imaging of soft magnetic materials by transmission electron microsco py (TEM) is difficult due to the potentially saturating field of the micros cope's objective lens. Energy filtered Lorentz microscopy provides a low fi eld, high resolution domain imaging solution for soft magnetic materials. T his technique was successfully applied to a soft magnetic nanocrystalline a lloy to examine the domain configurations in a thin foil sample. A sample w ith composition Fe44Co44Zr7B4Cu1 annealed at 650 degreesC for one hour was examined. Both Foucault and Fresnel methods were used to develop a clear pi cture of the relationship between the microstructure and domain structure o f this alloy. Magnetic domain maps were created showing some regions of the sample with irregularly shaped domains, which are characteristic of amorph ous alloys. Other regions contained relatively large grains with the magnet ization in a circular in-plane configuration (presumably due to shape aniso tropy).