Write Head With DC Current-Driven Energy-Assisted Magnetic Recording

Abstract

A magnetic write head carrying dc current is studied using micromagnetic simulations. Without the dc current, the stochastic nature of write pole magnetization switching is driven by the nucleation and propagation of the magnetic domains inside the write pole once the writer changes the polarity. These chaotic switching events produce a non-repeatable field seen by the media at every transition and results in lower bit per inch (BPI) and areal density capabilities (ADC). We are proposing a method to tackle this issue by applying a small dc current, which generates a magnetic field seen by the writer’s magnetic volume and ultimately helps to reduce the stochastic nature of writer magnetization switching. We are presenting flux jitter reduction as a function of bias current and show the corresponding experimentally observed improvements. We also have studied magnetic write track pitch expansion and contraction due to the current-induced field in the shields.