| 摘要 |
PURPOSE:To improve the yield rate of indefectible goods in head production by discriminating whether the Barkhausen phenomenon exists or not to evaluate a permeability magnetic thin film as it is and detecting the cause of a noise abnormality of the thin film before the thin film is worked into a head. CONSTITUTION:The surface of a permeability magnetic thin film 2 which is laminated on a nonmagnetic plane substrate 1 and is a sample to be detected is brought into contact with a gap part 4 of what is called a ring-type head 3, and a signal electromotive force induced in a coil 5 of this ring head 3 is displayed on an oscilloscope 10 through an amplifier 9. The fing-type head 3 is incorporated in a sample plating table 6. The sample to be examined and the ring-type head 3 are placed in center parts of Helmholtz coils 7 and 7', and an AC or DC magnetic field is impressed to them by an external power source 8. By this constitution, an impulsive noise signal is displayed on the oscilloscope 10 if the Barkhausen phenomenon is caused in the sample magnetic film 2, and thus, the sample magnetic film 2 is evaluated easily to be defective goods. |
