New structured metal-in-gap head for high density and high transfer rate recordings

A metal-in-gap (MIG) head with improved structure which achieves high output voltage and low inductance is investigated. The structure is optimized by three-dimensional finite-element calculation. In order to reduce read-back pulse distortions, a fabrication process using nanocrystalline Fe-Ta-C film (Nanomax) is introduced. Experimental results show that this head has outstanding advantages over the conventional MIG heads with regard to low inductance (2.2 nH/turn at 1.0 MHz), high normalized output voltage (4.2 and 3.0 μV_p-p/√μH×μm×m/s at 1.0 and 6.0 MHz, respectively) and small read-back asymmetry instability (5.0 ns at 4.0 MHz)