Heat-assisted magnetic recording with shaped magnetic and thermal fields
Devices and methods are provided for heat-assisted magnetic recording (HAMR). In an illustrative example, a device includes a magnetic write pole having a convex pole tip; a magnetic opposing pole longitudinally displaced from the magnetic write pole; and a thermal-source component disposed proximate to the magnetic write pole and comprising a laterally elongated thermal-source peg disposed proximate to the convex pole tip.
1. A device comprising:
a magnetic write pole having a convex pole tip;
a magnetic opposing pole longitudinally displaced from the magnetic write pole; and
a thermal-source component disposed proximate to the magnetic write pole and comprising a laterally elongated thermal-source peg having a concave portion at a trailing edge thereof disposed proximate to the convex pole tip, wherein the concave portion of the thermal-source peg is facing the convex pole tip of the magnetic write pole.
2. The device of claim 1 , wherein the thermal-source peg is configured to emit electromagnetic radiation.
3. The device of claim 1 , wherein the thermal-source component comprises a near field transducer, and the near field transducer comprises the thermal-source peg.
4. The device of claim 3 , further comprising a solid immersion mirror, wherein the near field transducer is disposed adjacent to the solid immersion mirror.
5. The device of claim 3 , further comprising a solid immersion lens, wherein the near field transducer is disposed adjacent to the solid immersion lens.
6. The device of claim 1 , wherein the thermal-source peg comprises dual laterally offset nanorods, wherein a central gap is defined between the nanorods.
7. The device of claim 1 , wherein the thermal-source peg is composed at least partly of one or more of gold, silver, copper, or aluminum.
8. The device of claim 1 , wherein the magnetic write pole provides a saturation magnetization of greater than 1.6 tesla.
9. A device comprising:
a magnetic medium;
a suspension apparatus; and
a magnetic head, disposed on the suspension apparatus and positionable thereby proximate to the magnetic medium;
wherein the magnetic medium comprises:
a substrate; and
a first magnetic layer disposed on the substrate; and
wherein the magnetic head comprises:
a magnetic write pole having a magnetic pole tip with an ellipsoidal pole tip face oriented in a forward longitudinal direction;
a magnetic opposing pole disposed at a forward longitudinal displacement from the magnetic write pole; and
a near field transducer disposed proximate to the magnetic write pole, comprising a near field transducer peg disposed proximate to the pole tip, wherein the near field transducer peg is elongated along a lateral dimension orthogonal to the longitudinal dimension.
10. The device of claim 9 , wherein the near field transducer peg comprises a concave surface proximate to and facing the magnetic pole tip.
11. The device of claim 9 , wherein the near field transducer peg comprises a flat surface proximate to and facing the magnetic pole tip.
12. The device of claim 9 , wherein the near field transducer peg comprises dual distal nanorods proximate to and facing the magnetic pole tip, wherein the nanorods define a gap between them proximate to the magnetic pole tip.
13. The device of claim 9 , wherein the first magnetic layer is formed of an alloy that comprises two or more of cobalt, iron, nickel, niobium, tin, chromium, platinum, palladium, neodymium, or samarium, and has a coercivity of between 25 and 100 kilooersteds.
14. The device of claim 9 , wherein the magnetic medium comprises a second magnetic layer disposed between the substrate and the first magnetic layer, wherein the second magnetic layer is formed of one or more of iron, cobalt, boron, aluminum, nitrogen, silicon, zirconium, niobium, or tantalum, and has a lower magnetic coercivity than the first magnetic layer.
15. The device of claim 9 , wherein the near field transducer is disposed proximate to a solid immersion mirror comprising one or more of silicon, titanium, oxide, nitride, or sulfide.
16. The device of claim 9 , wherein the magnetic medium further comprises one or more of: an insulating layer, a thermal barrier layer, a heat sink layer, a laminate layer, a dielectric layer, an overcoat layer, or a lubricating layer.
17. A process comprising:
positioning a magnetic recording head proximate to and in motion relative to a magnetic recording medium, wherein the direction of the relative motion of the magnetic recording head defines a down-track direction;
emitting optical energy from an optical source on the magnetic recording head onto the magnetic recording medium with an isothermal footprint that has a greater length in a cross-track direction than in the down-track direction, thereby temporarily reducing the magnetic coercivity of a heated portion of the magnetic recording medium; and
generating a magnetic field between a convex magnetic write pole positioned proximate to and oriented facing the optical source on the magnetic recording head, and a magnetic opposing pole disposed on the magnetic recording head, wherein the magnetic field passes through the heated portion of the magnetic recording medium.
18. The process of claim 17 , further comprising emitting the optical energy using a means for providing that an isothermal profile of the heated portion has a trailing edge, relative to the motion of the magnetic recording head, that is relatively straight, relative to a remaining portion of the isothermal profile.