Study on high field transfer curves of GMR heads with damaged pinned layer by ESD

In order to study the effect of ESD on antiferromagnetic layer of GMR heads, transfer curves of GMR heads using high-field QST (quasi static tester) were investigated. Transfer curves of GMR heads vary in waveform by applying of ESD damage, but there are many kinds of waveforms of transfer curves of after ESD damaged heads. Analysis of these damaged heads in magnetic state using high-field QST suggested that ESD damage would degrade the interlayer exchange coupling between pinned layer and anti-ferro magnetic layer.