Pre-assisting microwave magnetic recording based on spin-hall nano-oscillators
The present embodiments relate to a pre-assisted microwave assisted magnetic recording (PA-MAMR) write head that utilizes spin-Hall nano-oscillators (SHNOs). The SHNO can include a free layer and a spin-hall layer comprising a spin-hall material(s). The SHNO(s) can be disposed in a leading shield (LS) region and can be used to pump energy into the media before the writing process. A spin-torque oscillator (STO) utilized in other write head designs can be replaced with SHNOs, which can pre-excite the media and let the media oscillation damp over time and then switch under the writer field.
1 . A pre-assist microwave-assisted magnetic recording (PA-MAMR) write head comprising:
a magnetic main pole (MP) comprising a tip portion;
a hot seed (HS) and a write gap (WG) disposed adjacent to the MP and configured to collect a magnetic flux from the MP;
a magnetic leading-edge taper (LET) disposed on a first side of the tip portion of the MP and creating a taper in the first side of the tip portion of the MP; and
a spin-hall nano oscillator (SHNO) disposed adjacent to a leading shield (LS) and the LET, wherein the SHNO comprises a free layer and a spin-hall layer.
2 . The PA-MAMR write head of claim 1 , further comprising:
a magnetic side shield (SS) disposed adjacent to the HS and configured to confine the magnetic flux in a cross-track direction.
3 . The PA-MAMR write head of claim 1 , wherein a center portion of the LET comprises an insulator to define a current path for the SHNO.
4 . The PA-MAMR write head of claim 1 , wherein the free layer comprises a magnetic material including any of a Cobalt-Platinum (Co/Pt) multilayer, a Cobalt-Palladium (Co/Pd) multilayer, or a Cobalt-Iron-Boron (CoFeB)/Magnesium Oxide (MgO) multilayer, such that the free layer is capable of exhibiting a circular oscillation mode.
5 . The PA-MAMR write head of claim 1 , wherein the spin-hall layer comprises a magnetic material including any of an Iron-Platinum alloy (FePt), a manganese-tin alloy (Mn 3 Sn), and an Iridium-Manganese alloy (IrMn 3 ), such that the spin-hall layer is configured to generate an out-of-plane polarized spin current.
6 . The PA-MAMR write head of claim 1 , wherein the spin-hall layer comprises a a perpendicular/in-plane coupled ferromagnetic trilayer comprising multiple stacked ferromagnetic layers or a Cobalt-Gadolinium (Co/Gd) multilayer.
7 . The PA-MAMR write head of claim 1 , wherein the free layer is configured to have an in-plane configuration by comprising a magnetic material that includes a Nickel-Iron (NiFe) alloy or a Iron-Cobalt (FeCo) alloy that is capable of exhibiting either an elliptical oscillation mode or a circular oscillation mode.
8 . The PA-MAMR write head of claim 1 , wherein the spin-hall layer is configured to exhibit in-plane spin-polarized spin current with a spin-hall angle by comprising a material including any of Platinum (Pt), Gold (Au), Tantalum (Ta), Tungsten (W), a Gold-Platinum (AuPt) alloy, an Iron-Silicon (FeSi) alloy, or a topological spin-Hall material including any of Tungsten ditelluride (WTe 2 ), molybdenum ditelluride (MoTe 2 ), or a niobium arsenide (NbAs).
9 . The PA-MAMR write head of claim 1 , wherein the free layer is pinned in an out-of-plane direction or an in-plane direction using synthetic anti-ferromagnetic (SAF) and/or shape anisotropy.
10 . The PA-MAMR write head of claim 1 , wherein a thickness of free layer ranges from 5 nanometers (nm) to 20 nm, and wherein a width of free layer ranges from 30 nm to 400 nm, and wherein a height of free layer ranges from 20 nm to 400 nm.
11 . The PA-MAMR write head of claim 1 , wherein the SHNO comprises the spin-hall layer comprising a negative magnetization is disposed on top of the free layer such that the spin-hall layer is disposed adjacent to the LET, and wherein the free layer is disposed on top of a second spin-hall layer comprising a positive magnetization.
12 . The PA-MAMR write head of claim 1 , wherein the SHNO comprises the spin-hall layer comprising a positive magnetization disposed on top of the free layer such that the spin-hall layer is disposed adjacent to the LET, and wherein the free layer is disposed on top of a second spin-hall layer comprising a negative magnetization.
13 . The PA-MAMR write head of claim 1 , wherein the PA-MAMR write head is part of a recording device in a head arm assembly, wherein the recording device is connected to a slider and a load beam, wherein the load beam is connected to a suspension configured to support the recording device and the slider.
14 . A head arm assembly comprising:
a recording head including a slider and a device connected to the slider, the device including:
a main pole (MP);
a magnetic leading-edge taper (LET) disposed on a first side of a tip portion of the MP and configured to create a taper in the first side of the MP; and
a spin-hall nano oscillator (SHNO) disposed adjacent to a leading shield (LS) and the LET, wherein the SHNO comprises a free layer and a spin-hall layer;
a load beam connected to the recording head; and
a suspension connected to the load beam and configured to support the recording head.
15 . The head arm assembly of claim 14 , wherein the device further comprises:
a hot seed (HS) and a write gap (WG) disposed adjacent to the MP and configured to collect a magnetic flux from the MP;
a magnetic side shield disposed adjacent to the HS and configured to confine the magnetic flux in a cross-track direction; and
an insulator at a center portion of the LET to define a current path for the SHNO.
16 . The head arm assembly of claim 14 , wherein the SHNO comprises the spin-hall layer comprising a negative magnetization disposed on top of the free layer such that the spin-hall layer is disposed adjacent to the LET.
17 . The head arm assembly of claim 14 , and wherein the free layer is disposed on top of a second spin-hall layer comprising a positive magnetization such that the free layer is disposed adjacent to the LET.
18 . A method for manufacturing a write head, the method comprising:
disposing a hot seed (HS) and a write gap (WG) disposed adjacent to a main pole (MP), wherein the HS and the WG are configured to collect a magnetic flux from the MP;
disposing a magnetic side shield (SS) adjacent to the HS, the SS configured to confine the magnetic flux in a cross-track direction;
disposing a magnetic leading-edge taper (LET) on a first side of a tip portion of the MP, wherein the LET creates a taper in the first side of the MP; and
disposing a spin-hall nano oscillator (SHNO) adjacent to a leading shield (LS) and the LET, wherein the SHNO comprises a free layer and a spin-hall layer.
19 . The method of claim 18 , further comprising:
adding an insulator to a center portion of the LET to define a current path for the SHNO.
20 . The method of claim 18 , further comprising:
pinning the free layer in an out-of-plane direction or an in-plane direction using synthetic anti-ferromagnetic (SAF) and/or shape anisotropy;
disposing the free layer on top of the spin-hall layer comprising a positive magnetization; and
disposing a second spin-hall layer comprising a negative magnetization on top of the free layer such that the second spin-hall layer is disposed adjacent to the LET.