A needle magnetizing arrangement (1) comprising a controller (4) adapted to generate a first magnetic field (F) for magnetizing a needle (2), and a magnetic field sensor (5) adapted to generate a signal based on a second magnetic field (F.sub.R) of the needle (2).

A tunneling magnetoresistive (TMR) read head for magnetic tape has a tape-bearing surface (TBS) and includes a first magnetic shield, a first gap layer on the first shield, a TMR sensor on the first gap layer and recessed from the TBS, a second gap layer on the TMR sensor, a second magnetic shield on the second gap layer, and a magnetic flux guide between the first and second gap layers between the TBS and the recessed TMR sensor. The first gap layer has an insulating portion with an edge at the TBS and a non-magnetic electrically-conducting portion recessed from the TBS, with the TMR sensor located on the conductive portion. The sense current is between the two shields. An insulating isolation layer may be located between the first gap layer and the first shield layer with the sense current being between the second shield and the first gap layer.

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 spin torque transfer (STT) assisted magnetic recording structure is disclosed wherein a magnetic flux guiding (MFG) device is formed between a main pole (MP) trailing side and a trailing shield (TS). The MFG device has a field generation layer (FGL) separated from first and second spin polarization (SP) layers by first and second non-magnetic layers, respectively. First and second SP layers have magnetizations in opposite directions so that when a direct current of sufficient magnitude is applied from the MP to TS, or from the TS to MP in other embodiments, FGL magnetization flips to a direction toward the MP and opposes a write gap field flux thereby enhancing the write field. Additive torque from two SP layers on the FGL enables lower current density for FGL flipping or a greater degree of FGL flipping at a given current density compared with MFG schemes having a single SP layer.

A spin torque transfer (STT) assisted magnetic recording structure is disclosed wherein a magnetic flux guiding (MFG) device is formed between a main pole (MP) trailing side and a trailing shield (TS). The MFG device has a field generation layer (FGL) separated from first and second spin polarization (SP) layers by first and second non-magnetic layers, respectively. First and second SP layers have magnetizations in opposite directions so that when a direct current of sufficient magnitude is applied from the MP to TS, or from the TS to MP in other embodiments, FGL magnetization flips to a direction toward the MP and opposes a write gap field flux thereby enhancing the write field. Additive torque from two SP layers on the FGL enables lower current density for FGL flipping or a greater degree of FGL flipping at a given current density compared with MFG schemes having a single SP layer.

An apparatus according to one embodiment includes a substrate having a media bearing surface, and a first shield above the substrate. The first shield has a media facing side recessed from a plane extending along the media bearing surface of the substrate. A current-perpendicular-to-plane sensor is located above the substrate, the sensor having a media facing side recessed from the plane extending along the media bearing surface of the substrate. An electrically nonconductive first film is positioned on the media facing sides of the first shield and sensor. A second film is positioned on a media facing side of the first film, the second film comprising a refractory metal.

An apparatus according to one embodiment includes a substrate having a media bearing surface, and a first shield above the substrate. The first shield has a media facing side recessed from a plane extending along the media bearing surface of the substrate. A current-perpendicular-to-plane sensor is located above the substrate, the sensor having a media facing side recessed from the plane extending along the media bearing surface of the substrate. An electrically nonconductive first film is positioned on the media facing sides of the first shield and sensor. A second film is positioned on a media facing side of the first film, the second film comprising a refractory metal.