Control of magnetostrictive vibration of amorphous ribbons by magnetic patterns

A contactless readable medium using a combination of amorphous magnetostrictive ribbon and semihard magnetic material has been investigated. The data are recorded onto the semihard magnetic material, whereas the readout utilizes the fact that the appearance of higher-order resonant peaks of the magnetostrictive vibration of the ribbon by the application of an ac magnetic field can be controlled by the leakage magnetic flux from the semihard material. The effect of the leakage magnetic flux generated during longitudinal magnetic recording on the semihard magnetic material by MIG head as a localized bias magnetic field has been examined. The results of using a direct magnetic field from a pair of single-pole heads as a localized bias magnetic field has been further examined; determination of wavelength recorded on the semihard magnetic material also has been done. As a result of observing the power spectrum in the ac magnetic field of the medium combining amorphous magnetostrictive ribbon (Metglas 2826 MB) of 80 × 5 × 0.04 mm3 and semihard magnetic material (CuNiFe alloy) of 100 × 10 × 0.2 mm3, the resonant peak of the amorphous magnetostrictive ribbon has been almost individually detected from the second to fifth orders corresponding to the recorded magnetization patterns.