An experimental study of head-disk clearance sensitivity and instabilities in magnetic recoding heads with adaptive flying height

Abstract

We did an experimental study to examine the head-to-media spacing (HMS) sensitivity of electrical performance of perpendicular recording system with an adaptive flying height (AFH) heater. It also focused on the effect of the temperature rise due to the AFH heater on the instability and noise of tunneling magnetoresistance (TMR) sensors. It is firstly reported that the high temperature rise from the AFH heater induces head instabilities. The signatures on the transfer curve indicate that the flipping of a synthetic antiferromagnet (SAF) edge magnetization causes these instabilities. The thermal stress potentially reduces the exchange-bias field and thermal stability of SAF layers and an antiferromagnetic (AFM) layer allowing flipping the SAF edge magnetization.