Measurements of magnetic characteristics of thin film heads using magneto-optical method

Using a micro-Kerr magneto-optic apparatus, magnetization curves of thin film heads were measured. Relationships between repeatability of the magnetization process and readback wave form distortion were examined. In yokes made of positive magnetostriction NiFe the trianglar edge domains were found to be large, the magnetization process was not repeatable and readback wave form distortion was observed. For negative magnetostrictive yokes, the edge domains were smaller, the magnetization process was repeatable and wave form distortion was not observed.