High-field gradient single-pole head with an improved pole structure

The relationship between the head field and the pole structure in a single-pole head is investigated by finite-element method calculation. The calculation reveals that the regular single-pole head does show a relatively large field gradient with a maximum of 150 Oe/mn, which is crucial for high-resolution recording, but only for relatively large field strength. By placing an additive pole in the vicinity of the main pole, the head-field gradient is improved. The new pole structure increases the gradient up to 250 Oe/nm. The large field gradient is obtained in a wider range of field strength than the regular single-pole head. The calculation also shows a simulated recorded transition when the large head field gradient becomes narrow.