Degaussing of Write Heads in Perpendicular Magnetic Recording

This paper introduces the idea of degaussing of perpendicular magnetic recording (PMR) heads, the approach generally accepted by the magnetic recording industry. Basic theoretical aspects of degaussing are discussed. A simplified approach based on write current turnoff is first studied. Second, an advanced degaussing method involving a sequence of write pulses of opposite polarities and decaying amplitude is analyzed using micromagnetic modeling tools. Dependences on degauss waveform parameters like frequency and duration are studied to provide guidance to find optimal solutions for reliable writer degaussing.