Perpendicular magnetic recording head having a recessed magnetic base layer
View Patent ↗A method and system for providing a magnetic transducer having an air-bearing surface (ABS) are described. The magnetic transducer includes a base layer, a perpendicular magnetic recording (PMR) pole on the base layer, an additional pole, a write shield, a write gap between the PMR pole and a portion of the write shield, and coil(s) that energize at least the additional pole. The base layer includes a first portion proximate to the ABS and a second portion recessed from the ABS. The first portion is nonmagnetic, while the second portion is magnetic. The PMR pole has a first front portion proximate to the ABS. The additional pole has a second front portion recessed from the ABS. At least a portion of the additional pole resides between the PMR pole and write shield. At least a portion of the write gap resides on the front portion of the PMR pole.
1. A magnetic transducer having an air-bearing surface (ABS), the magnetic transducer comprising:
a base layer including a first portion proximate to the ABS and a second portion recessed from the ABS, the first portion being nonmagnetic, the second portion being magnetic;
a perpendicular magnetic recording pole having a first front portion proximate to the ABS, the perpendicular magnetic recording pole residing on the base layer, the perpendicular magnetic recording pole having a bottom surface and a top surface opposite to the bottom surface, the bottom surface being adjacent to the base layer; an additional pole recessed from the ABS, a first portion of the additional pole being adjacent to the top surface of the perpendicular magnetic recording pole, a second portion of the additional pole extending further from the ABS than the perpendicular magnetic recording pole;
a write gap, at least a portion of the write gap residing on the front portion of the perpendicular magnetic recording pole;
a write shield, the write gap residing between the perpendicular magnetic recording pole and a portion of the write shield, at least a portion of the additional pole residing between the perpendicular magnetic recording pole and the write shield; and
at least one coil for energizing at least the additional pole.
2. The magnetic transducer of claim 1 wherein the second portion of the base layer has a front residing between the ABS and a front surface of the additional pole.
3. The magnetic transducer of claim 2 wherein the front of the second portion of the base layer is recessed from the ABS by not more than one micron.
4. The magnetic transducer of claim 3 wherein the front of the second portion of the base layer is recessed from the ABS by not more than two hundred fifty nanometers.
5. The magnetic transducer of claim 1 wherein the first portion of the base layer includes at least one of NiP, NiNb, CoB, NiCr, Ru, and AlOx.
6. The magnetic transducer of claim 1 wherein the first portion of the base layer further includes a chemical mechanical planarization stop layer.
7. The magnetic transducer of claim 6 wherein the chemical mechanical planarization stop layer includes at least one of Cr, Ta, Ru, and diamond-like carbon.
8. The magnetic transducer of claim 1 wherein the second portion of the base layer has a high saturation magnetization.
9. The magnetic transducer of claim 8 wherein the high saturation magnetization is at least one Tesla and not more than 2.5 Tesla.
10. The magnetic transducer of claim 8 wherein the second portion of the base layer includes at least one of Fe, Co, Ni, and CoFe.
11. The magnetic transducer of claim 1 wherein the top surface of the perpendicular magnetic recording pole is in contact with the first portion of the additional pole and the perpendicular magnetic recording pole resides between the base layer and the shield.
12. The magnetic transducer of claim 11 further comprising:
a back gap distal from the ABS, the additional pole extending to the back gap.
13. A magnetic transducer having an air-bearing surface (ABS), the magnetic transducer comprising:
a base layer including a first portion proximate to the ABS and a second portion recessed from the ABS, the first portion being nonmagnetic, the second portion being magnetic, having a high saturation magnetization and having a front recessed from the ABS by not more than one micron;
a perpendicular magnetic recording pole having a first front portion proximate to the ABS, a bottom surface and a top surface, the base layer being adjacent to the bottom surface;
a back gap distal from the ABS;
an additional pole having a second front portion recessed from the ABS, a first portion of the additional pole being adjacent to and in contact with the to surface of the perpendicular magnetic recording pole, a second portion of the additional pole extending further from the ABS than the perpendicular magnetic recording pole, the second portion of the additional pole extending to the back gap, the front of the second portion of the base layer residing between the ABS and the second front Portion of the additional pole;
a write gap, at least a portion of the write gap residing on the front portion of the perpendicular magnetic recording pole;
a write shield, the write gap residing between the perpendicular magnetic recording pole and a portion of the write shield, at least a portion of the additional pole residing between the perpendicular magnetic recording pole and the write shield, the second front of the additional pole being at least 0.25 micrometers from the portion of the write shield, the perpendicular magnetic recording pole residing between the base layer and the shield; and
at least one coil for energizing at least the additional pole.
14. A head comprising:
a read transducer; and
a magnetic write transducer having an air-bearing surface (ABS), the magnetic transducer further including a base layer, a perpendicular magnetic recording pole, an additional pole, a write gap, a write shield, and a coil, the base layer including a first portion proximate to the ABS and a second portion recessed from the ABS, the first portion being nonmagnetic, the second portion being magnetic and having a front, the perpendicular magnetic recording pole having a first front portion proximate to the ABS, the perpendicular magnetic recording pole having a bottom surface and a top surface opposite to the bottom surface, the bottom surface being adjacent to the base layer, the additional pole having a second front portion recessed from the ABS, a first portion of the additional pole being adjacent to the top surface of the perpendicular magnetic recording pole, a second portion of the additional pole extending further from the ABS than the perpendicular magnetic recording pole, the front of the second portion of the base layer being between the ABS and the second front of the additional pole, at least a portion of the write gap residing on the front portion of the perpendicular magnetic recording pole, the write gap residing between the perpendicular magnetic recording pole and a portion of the write shield, at least a portion of the additional pole residing between the perpendicular magnetic recording pole and the write shield, the at least one coil for energizing at least the additional pole; and
a slider, at least one of the read transducer and the magnetic write transducer residing on the slider.
15. The head of claim 14 wherein the top surface of the perpendicular magnetic recording pole is in contact with the first portion of the additional pole and the perpendicular magnetic recording pole resides between the base layer and the shield.
16. The head of claim 15 wherein the magnetic write transducer further includes:
a back gap distal from the ABS, the additional pole extending to the back gap.