Abstract: Magnetic thin film structures are disclosed including a laminate of a layer of nonmagnetic material sandwiched between first and second layers of magnetic material and at least one edge closure layer of magnetic material disposed on a side edge of the laminate with the edge closure layer being in magnetic contact with the first and second layers of magnetic material. The edge closure layer eliminates magnetic edge closure domains and magnetic edge-curling walls in the yoke and poletip regions, or in a fluxguide of a magnetic recording head to substantially eliminate Barkhausen noise and wall network instabilities. Multiple layer laminates are also disclosed having a plurality of nonmagnetic layers each of which are sandwiched between layers of magnetic material and wherein the laminate includes edge closure layers that contact all the magnetic layers. Several methods are disclosed for fabricating the laminate.

Abstract: Magnetic thin film structures including a laminate of a layer of nonmagnetic material sandwiched between first and second layers of magnetic material and at least one edge closure layer of magnetic material disposed on a side edge of the laminate with the edge closure layer being in magnetic contact with the first and second layers of magnetic material. The edge closure layer eliminates magnetic edge closure domains and magnetic edge-curling walls in the yoke and poletip regions, or in a fluxguide of a magnetic recording head to substantially eliminate Barkhausen noise and wall network instabilities. Multiple layer laminates are also disclosed having a plurality of nonmagnetic layers each of which are sandwiched between layers of magnetic material and wherein the laminate includes edge closure layers that contact all the magnetic layers. Several methods are disclosed for fabricating the laminate. In one class of technique, the side edges are deposited together with a top layer in a single plating operation.

Abstract: Magnetic thin film structures are disclosed including a laminate of a layer of nonmagnetic material sandwiched between first and second layers of magnetic material and at least one edge closure layer of magnetic material disposed on a side edge of the laminate with the edge closure layer being in magnetic contact with the first and second layers of magnetic material. The edge closure layer eliminates magnetic edge closure domains and magnetic edge-curling walls in the yoke and poletip regions, or in a fluxguide of a magnetic recording head to substantially eliminate Barkhausen noise and wall network instabilities. Multiple layer laminates are also disclosed having a plurality of nonmagnetic layers each of which are sandwiched between layers of magnetic material and wherein the laminate includes edge closure layers that contact all the magnetic layers. Several methods are disclosed for fabricating the laminate.

Abstract: The problem of characterizing metallic magnetic particles as suitable or unsuitable for use in a high density magnetic recording media is believed to have been solved by use of a figure of merit designated as "W/H.sub.c ", and defined herein.It has been found that metallic magnetic particles which exhibit a W/H.sub.c of about 1.2 or less offer the most desirable magnetic recording characteristics for high density magnetic recording media. With this characterization technique available, it has been determined that most quantities of metallic magnetic cobalt-phosphorus particles produced by chemical reduction have W/H.sub.c 's greater than 1.2, and are unsuitable for use in high density magnetic recording media. Using W/H.sub.c, it has been possible to recognize those metallic particles which are suitable for use in high density recording media, and to engage in experimentation to determine what methods of manufacturing are required for the production of suitable high density recording particles.