The behavior of noise-after-write in thin film heads was studied. The probability of noise-after-write events was decreased by applying a constant amplitude current or a decay amplitude current to the head coil, after shutting off a recording current. A constant amplitude current has a higher ability to decrease noise-after-write than a decay amplitude current.
Comparison between the noise pulse of a Ni-Fe head and that of a Co-Ta-Zr amorphous head shows that the former head has a wider pulse width than the latter head.