Abstract: A method employs an RF magnetron sputtering system under specific process conditions for making shield and pole piece ferromagnetic layers of a read write magnetic head wherein the magnetic anisotropy HK of the ferromagnetic layers is substantially maintained without easy axes switching when annealed along their hard axes in the presence of a magnetic field (hard axis annealing).

Abstract: A tunnel valve sensor has a flux guide which has at least one iron nitride (FeN) layer and preferably a lamination of iron nitride (FeN) and nickel iron molybdenum (NiFeMo) layers wherein in the first instance the read gap is reduced and in the second instance the read gap is reduced and the sensitivity of the read head is increased.

Abstract: A spin valve sensor is provided with a negative ferromagnetic coupling field −HFC for properly biasing a free layer and a spin filter layer is employed between the free layer and a capping layer for increasing the magnetoresistive coefficient dr/R of the spin valve sensor. A top portion of the free layer is oxidized for improving the negative ferromagnetic coupling field −HFC when the spin filter layer is employed for increasing the magnetoresistive coefficient dr/R.

Abstract: A spin valve sensor has a pinned layer structure which includes first, second and third pinned films wherein the first pinned film is nickel iron and is located between the second and third pinned films which are cobalt iron. This structure significantly reduces the magnetostriction of the free layer structure of the spin valve sensor to an acceptable level.

Abstract: A merged magnetic head has a top first pole tip layer and a bottom second pole tip layer which are located entirely between an air bearing surface and a coil layer. A write gap layer separates the pole tip layers from one another at the ABS. A zero throat height (ZTH) defining layer is located adjacent the top gap layer between the pole tip layers and is recessed from the ABS so as to further separate the pole tip layers from one another at a location recessed from the ABS so as to define the zero throat height of the write head where the first and second pole pieces first commence to separate from one another after the ABS.

Abstract: A half metallic phase iron oxide (Fe3O4) layer is employed in either or both of a pinned layer structure and a free layer structure in a spin valve sensor for filtering minority electrons and reflecting majority electrons with respect to a spin scattering region for increasing the magnetoresistive coefficient dr/R of a spin valve sensor.

Abstract: A magnetic head assembly includes first and second pole pieces and first and second coil layers wherein the second pole piece has a ferromagnetic pole tip which forms a portion of an air bearing surface and defines a track width of a write head. A write gap layer is located between the first pole piece and the pole tip. A dielectric first insulation layer interfaces first and second side surfaces of the pole tip and is located between the first and second coil layers. The second pole piece has a ferromagnetic second pole piece structure which is magnetically connected to each of the pole tip and the first pole piece and extends across the second coil layer. In a first embodiment the second pole piece structure is a single layer and in a second embodiment the second pole piece structure has front and back components with a flat laminated second pole piece yoke layer located therebetween.

Abstract: In the manufacture of a combined magnetic head, milling time for notching a first pole piece of the head's write element is reduced by constructing the first pole piece with a notching layer on a first pole piece layer, the notching layer having first and second corners adjacent first and second side walls of the second pole tip. The first pole piece layer has a wide lateral expanse, and the notching layer has a narrow lateral expanse. The width of the notching layer is preferably 0.2 &mgr;m to 2.0 &mgr;m wider than a target track width of the second pole tip. With this arrangement, the notching layer has first and second side walls that project 0.10 &mgr;m to 1.0 &mgr;m. laterally, beyond first and second side walls, respectively, of the second pole tip. The thickness of the notching layer is preferably between 0.1 &mgr;m to 1.0 &mgr;m. Accordingly, full notching of the notching layer can be achieved by milling a small-corner in a range of 0.10 &mgr;m by 0.10 &mgr;m to 1.0 &mgr;m by 1.

Abstract: A tunnel valve sensor and flux guide has improved flux transfer therebetween by providing a magnetic oxide insulation layer which is located between and interfaces a back surface of the flux guide and a front surface of the tunnel valve sensor. Since this insulation layer has magnetic properties an increased amount of flux is transferred between the flux guide to the tunnel valve sensor for rotating a magnetic moment of a free layer in the tunnel valve sensor.

Abstract: A first read gap layer has a resistance RG1 between a first shield layer and one of the first and second lead layers of a read head and the second read gap layer has a resistance RG2 between a second shield layer and said one of the first and second lead layers of the read head. A connection is provided via a plurality of resistors between a first node and each of the first and second shield layers wherein the plurality of resistors includes at least first and second resistors RS1 and RS2 and the first node is connected to said one of the first and second lead layers. A second node is located between the first and second resistors RS1 and RS2. An operational amplifier has first and second inputs connected to the first and second nodes respectively so as to be across the first resistor RS1 and has an output connected to the first node for maintaining the first and second nodes at a common voltage potential. In a first embodiment the first and second shield layers are shorted together.

Abstract: A spin valve sensor is provided with a biasing layer which produces a demagnetizing field which supports a demagnetizing field from a pinned layer structure in counterbalancing a sense current field on the free layer structure. The biasing layer has a high resistance so that a sense current is not excessively shunted therethrough and is a specular reflector so as to reflect conduction electrons to increase a magnetoresistive coefficient dr/R of the sensor. In the preferred embodiment the pinned layer structure is an antiparallel (AP) pinned layer structure.

Abstract: A system for measuring the magnetostriction coefficient &lgr; of a sample material applied to a substrate element fixed at one end leaving the other end free to be deflected. An external rotating magnetic field of rotation frequency f and intensity Hext is applied to the cantilever substrate element the amplitude Am of the deflection of the free end is measured at each of a plurality of rotation frequency harmonics {fm} by, for example, using a plurality of lock-in amplifiers. The harmonic deflection amplitudes {Am} are combined to determine the magnetostriction coefficient &lgr; of the sample material. At an Hext equal to the sample saturation moment Msat and assuming a 15 Oe sample anisotropy Hk and coupling bias Hp, the error in the saturation magnetostriction coefficient &lgr;S measured according to this invention may be reduced by 80% to 90% over the error seen when using only the second harmonic deflection amplitudes A2.

Abstract: A free layer structure of a spin valve sensor includes a cobalt niobium or cobalt niobium hafnium layer for providing a negative magnetostriction which completely or partially counterbalances a positive magnetostriction of a cobalt or cobalt iron layer wherein the cobalt or cobalt iron layer interfaces a copper spacer layer for increasing the magnetoresistive coefficient dr/R of the head. In one aspect of the invention the free layer structure consists of only the cobalt iron layer and the cobalt niobium or cobalt niobium hafnium layer.

Abstract: A free layer for a spin valve sensor includes a cobalt iron (CoFe) film which has an easy axis oriented perpendicular to an air bearing surface (ABS) of a read head and a nickel iron (NiFe) film which has an easy axis oriented parallel to the ABS and parallel to the major planes of the thin film layers. In a further embodiment the free layer is annealed at a high temperature in the presence of a field which is oriented perpendicular to the ABS.

Abstract: In a tunnel junction sensor a free layer structure has a cobalt iron (Co90Fe10) layer and a half metallic iron oxide (Fe3O4) layer and a pinned layer structure has a cobalt iron (Co50Fe50) layer and a half metallic iron oxide (Fe3O4) layer. Each of the iron oxide layers interfaces a barrier layer which is compatible therewith. The thicknesses of the iron oxide (Fe3O4) layers are less than the thicknesses of the other layers of the free and pinned layer structures.

Abstract: A method of fabricating a second pole piece layer of a write head is constructed using first and second photoresist layers which are sensitive to light with different bandwidths. The second photoresist layer, which is on top of the first photoresist layer, is light exposed with light that excludes light that would change the molecular structure of the first or bottom photoresist layer. After light exposure and development of the second photoresist layer to provide an opening for yoke and back gap portions of the second pole piece layer, the first photoresist layer is light exposed with light that includes the light excluded in the light exposure step of the second photoresist layer. The light exposure of the first photoresist layer and its developing provides the first photoresist layer with an opening for electroplating the second pole tip of the second pole piece layer.

Abstract: A method of making read sensor with self-aligned low resistance leads is provided. In the method a masking step has been eliminated by employing first, second and third protective capping layers in the construction of the read sensor and first and second lead layers. The first capping layer serves as a protective layer for the read sensor sites, the second capping layer protects low resistance lead layer portions during removal of the first capping layer from high resistance lead layer sites and then serves as a sacrificial layer during removal of spin valve material from the low resistance lead layer sites. The third capping layer protects the first and second lead layers during milling of low resistance lead layer material in field regions about the read sensor and first and second lead layers. The method aligns front edges of the low resistance lead layer portions with a rear edge of the read sensor so as to lower the overall resistance of the lead layers.

Abstract: A method of making provides a smooth surface of a pinned or free layer interfacing a barrier layer in a tunnel junction sensor wherein the smooth surface is an oxidized monolayer of the pinned or free layer. After sputter depositing the pinned or free layer the layer is subjected to an oxygen (O2) atmosphere which is extremely low for a very short duration. In a preferred embodiment of the invention a partial thickness of the barrier layer is provided with a smooth surface by the same process after which a remainder thickness of the barrier layer is deposited and the barrier layer is exposed to oxygen (O2) to form an oxide of the deposited metal.

Abstract: A dual GMR or dual spin valve sensor has a self-pinned layer which has its magnetic moment pinned perpendicular to an air bearing surface by sense current fields from conductive layers in the dual spin valve sensor when a sense current is conducted therethrough. This scheme eliminates one of the antiferromagnetic pinning layers which is typically employed in a dual GMR or dual spin valve sensor. The self-pinned layer is thin so that its demagnetization field will not be greater than the sense current fields acting thereon. Because of the thinning of the self-pinned layer the spin valve effect of the spin valve sensor is degraded by scattering of conduction electrons at the boundary of the self-pinned layer.

Abstract: A cap layer structure includes first and second cap layers wherein the first cap layer is composed of a nonmagnetic metal and the second cap layer is composed of iron oxide. Both cap layers are specular reflectors which reflect conduction electrons back into a spin scattering region of a spin valve sensor without increasing the uniaxial anisotropy HK of a free layer structure within the spin valve sensor.