New high field single-pole head design with an ultra-fine coil

Improvement in head field of single-pole heads was investigated in terms of coil design. From a simple analysis on hollow cylinder-shaped coil, a quite strong field was found to be created for the coil with inner diameter less than 100 nm. According to this result, a new single-pole head having an ultra-fine coil at its main-pole tip was proposed. The field calculation with FEM showed the new head designed for 1 Tbit/in2 exhibited a strong field larger than 30 kOe owing to enhancement of coil field. Furthermore, a sub-return yoke placed close to the main pole improved head field gradient.