The high Bs sputtered amorphous MIG head with a minimized contour effect

It is known that the pseudo-gap in MIG (metal-in-gap) heads causes ripples in a playback frequency spectrum, which is called the contour effect, originating mainly from the formation of reacted magnetic layers during the heating process. To solve this problem, a low-temperature metal diffusion process at less than 350°C has been introduced for the head bonding. The constructed MIG heads are mainly composed of a Mn-Zn ferrite and a sputtered CoZrMoPd amorphous film with a high saturation flux density of 1.2 T. It was found, through the examination with Auger electron spectroscopy around the boundary between the amorphous film and the ferrite, that one could keep control of the formation of the undesired reacted layers by decreasing the applied temperature. It was also found that one could reduce the contour effect to such an extent that there were almost no ripples in the playback frequency spectrum down to less than 0.3 dB