DYNAMIC FIELD DISTRIBUTIONS OF THIN-FILM INDUCTIVE HEADS

Dynamic recording fields of thin film inductive disk drive heads and their relationships to drive current, pole thickness and pole materials have been investigated. Electron beam tomography was used to directly observe the recording fields. With permalloy heads, improved frequency responses were achieved by exciting the magnetic core with higher drive currents. However, increases in the pole thickness significantly degraded the frequency responses. The amorphous CoTaZr head showed superior frequency response, and constant field intensity was maintained up to 30 MHz, regardless of drive current.