A method of forming a sub-structure, suitable for use as a hot seed in a perpendicular magnetic recording head, is described. A buffer layer of alumina with a thickness of 50-350 Angstroms is formed by atomic layer deposition as a write gap. Thereafter, one or more seed layers having a body-centered cubic (bcc) crystal structure may be deposited on the buffer layer. Finally, a magnetic film made of FeCo or FeNi with a coercivity of 60-110 Oe is deposited on the seed layer(s) by a physical vapor deposition (PVD) method at a rate of 0.48 to 3.6 Angstroms per second. The magnetic film is preferably annealed at 220° C. for 2 hours in a 250 Oe applied magnetic field.

A method of forming a spin transfer torque reversal assisted magnetic recording (STRAMR) writer is disclosed wherein a spin torque oscillator (STO) has a flux guiding layer (FGL) wherein magnetization flips to a direction substantially opposing the write gap (WG) field when sufficient current (I.sub.B) density is applied across the STO between a trailing shield and main pole (MP) thereby enhancing the MP write field. The FGL has a center portion with a larger magnetization saturation×thickness (MsT) than in FGL outer portions proximate to STO sidewalls. Accordingly, lower I.sub.B density is necessary to provide a given amount of FGL magnetization flipping and there is reduced write bubble fringing compared with writers having a FGL with uniform MsT. Lower MsT is achieved by partially oxidizing FGL outer portions. In some embodiments, there is a gradient in outer FGL portions where MsT increases with increasing distance from FGL sidewalls.

A method of forming a spin transfer torque reversal assisted magnetic recording (STRAMR) writer is disclosed wherein a spin torque oscillator (STO) has a flux guiding layer (FGL) wherein magnetization flips to a direction substantially opposing the write gap (WG) field when sufficient current (I.sub.B) density is applied across the STO between a trailing shield and main pole (MP) thereby enhancing the MP write field. The FGL has a center portion with a larger magnetization saturation×thickness (MsT) than in FGL outer portions proximate to STO sidewalls. Accordingly, lower I.sub.B density is necessary to provide a given amount of FGL magnetization flipping and there is reduced write bubble fringing compared with writers having a FGL with uniform MsT. Lower MsT is achieved by partially oxidizing FGL outer portions. In some embodiments, there is a gradient in outer FGL portions where MsT increases with increasing distance from FGL sidewalls.

A spin transfer torque reversal assisted magnetic recording (STRAMR) writer is disclosed wherein a spin torque oscillator has a flux guiding layer (FGL) wherein magnetization flips to a direction substantially opposing the write gap (WG) field when sufficient current (I.sub.B) density is applied across the STO between a trailing shield and main pole (MP) thereby enhancing the MP write field. A key feature is that the FGL has a center portion with a larger magnetization saturation×thickness (MsT) than in FGL outer portions proximate to STO sidewalls. Accordingly, lower I.sub.B density is necessary to provide a given amount of FGL magnetization flipping and there is reduced write bubble fringing compared with writers having a FGL with uniform MsT. Lower MsT is achieved by partially oxidizing FGL outer portions. In some embodiments, there is a gradient in outer FGL portions where MsT increases with increasing distance from FGL sidewalls.

A spin transfer torque reversal assisted magnetic recording (STRAMR) writer is disclosed wherein a spin torque oscillator has a flux guiding layer (FGL) wherein magnetization flips to a direction substantially opposing the write gap (WG) field when sufficient current (I.sub.B) density is applied across the STO between a trailing shield and main pole (MP) thereby enhancing the MP write field. A key feature is that the FGL has a center portion with a larger magnetization saturation×thickness (MsT) than in FGL outer portions proximate to STO sidewalls. Accordingly, lower I.sub.B density is necessary to provide a given amount of FGL magnetization flipping and there is reduced write bubble fringing compared with writers having a FGL with uniform MsT. Lower MsT is achieved by partially oxidizing FGL outer portions. In some embodiments, there is a gradient in outer FGL portions where MsT increases with increasing distance from FGL sidewalls.

A method of manufacturing a magnetic-field sensor includes forming an insulating layer on a first surface of a substrate. First and second magnetoresistors are formed at different above the first surface of the substrate and are spaced apart from the first surface by different distances. The first and second magnetoresistors have respective main axes of magnetization transverse to one another, and respective secondary axes of magnetization transverse to one another. The method further includes forming a first magnetic-field generator configured to generate a first magnetic field having field lines along the main axis of magnetization of the first magnetoresistor, and forming a second magnetic-field generator configured to generate a second magnetic field having field lines along the main axis of magnetization of the second magnetoresistor.

A tunnel magnetoresistance (TMR) read head includes a first magnetic shield, a read sensor stripe located over the first magnetic shield, a second magnetic shield located over the sensor layer stack, an electrical isolation dielectric layer located on sidewalls of the read sensor stripe, and a pair of side shields located on the electrical isolation dielectric layer between the first magnetic shield and the second magnetic shield. The read sensor stripe includes a sensor layer stack containing a pinned layer stack, a non-magnetic electrically insulating barrier layer, and a ferromagnetic free layer. The side shields include nanocrystalline ferromagnetic particles, such as Fe, Co or CoFe, embedded in a non-magnetic dielectric material matrix, such as hafnium oxide.

A computer program product according to one embodiment includes a computer readable storage medium having program instructions embodied therewith. The program instructions area executable by a data processing system having at least one processor to cause the data processing system to apply, by the data processing system, a current to a lead of a tunneling magnetoresistance (TMR) sensor for inducing joule heating of the lead or a heating layer, the level of joule heating being sufficient to anneal a magnetic layer of the sensor; and maintain, by the data processing system, the current at the level for an amount of time sufficient to anneal the sensor.

Implementations described and claimed herein provide a system comprising an external magnetic field generator, wherein the external field magnetic field generator is configured to rock an effective annealing magnetic field between a first positive angle and a second negative angle compared to a desired pinning field orientation in an AFM/PL structure.

The present embodiments relate to a tunnel magnetoresistance (TMR) element. The TMR element can include a free layer comprising a metallic alloy that is doped using a dopant element. In some instances, the metallic alloy comprises a cobalt-iron (CoFe) alloy. The present embodiments relate to doping a small amount of an element (e.g., hafnium (Hf), tantalum (Ta), Yttrium (Y)) in a high flux CoFe layer of a tunnel magnetoresistance (TMR) element. The small amount of dopant can suppress a long-range order in the CoFe film. The amorphous state of a CoFe alloy can be induced by the dopant and result in a magnetically soft layer. A resistance of the TMR element can be modified based on an application of an external magnetic field to the free layer and the pin layer.