MFM images of a magnetic head and a recording medium obtained by using electrodeposited FeNi, Co, and FeCo tips show quite different features. These differences are explained by the saturation magnetization and the coercive force of the magnetic thin films electrodeposited on the W wires, In addition, we attempted to observe the magnetic structure of the tip by using magnetotactic bacteria that swim along the lines of the magnetic field originating from the poles on the tip.
