Relationship of Exciting Current to Noise-after-Write of Thin Film Head

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 the recording current. A constant-amplitude current was more effective for decreasing noise-after-write than a decay amplitude current. Comparison of the noise pulse of an Ni-Fe head and of a Co-Ta-Zr amorphous head showed that the former had a wider pulse width than the latter.