High moment laminated layer with nickel cobalt or nickel iron cobalt based alloy layer for first pole piece of write head

Abstract

A material is provided for the first shield and/or second shield/first pole piece layer of a merged MR head. The material employed is nickel cobalt (Ni,Co,) (wt. %) or a nickel iron cobalt alloy. In a second shield/first pole piece layer a further preferred embodiment is first and second layers wherein the first layer is nickel cobalt or a nickel iron cobalt alloy and the second layer is a laminate of a high magnetic material, such as iron nitride (FeN) laminated with aluminum oxide (Al,O,). The nickel cobalt or nickel iron cobalt alloy layers have a higher intrinsic anisotropic (H,) and can better withstand the processing fields employed during the various annealing steps in the construction of the head. Accordingly, the magnetic domains of the first and second shield layers do not change position from a desired parallel position to the ABS. By maintaining their parallel position, applied fields during the operation of the head, such as from the write head or the media, does not move the domain walls around to cause Barkhausen noise. The high magnetic moment laminated layer for the second shield/first pole piece layer serves as a good first pole piece flux conducting layer for the write head portion of the magnetic head. Accordingly, the second shield/first pole piece layer serves two functions, namely a stable shield for the read head and conducting flux for the write head.