Degaussing PMR Writer Poles: A Micromagnetic Modeling Study

This paper presents a study of the degauss process of a perpendicular magnetic writer pole using micromagnetic modeling as a tool. The dynamics of the yoke and the pole-tip magnetization relaxation during degauss are studied in detail, and the remanent field of the pole tip is used as a metric to measure the effectiveness of each of the degauss methods. Various aspects of the degauss current waveforms are investigated, such as frequency, duration, initial current amplitude, amplitude decay envelope, and overshoot. Some alternative waveforms, i.e., unipolar reverse pulse degaussing, have also been examined. It has been found for many of the parameters to have an optimal range outside of which the degauss effectiveness and efficiency are degraded.