US-12620412-B2 - Spintronic device comprising dual FGL and dual SPL to reduce perpendicular field at writing location

Abstract

The present disclosure is generally related to a magnetic recording device comprising a magnetic recording head. The magnetic recording head comprises a main pole, a hot seed layer, and a spintronic device disposed between the main pole and the hot seed layer. The spintronic device comprises two field generation layers (FGLs), two spin polarization layers (SPLs), and two spin kill layers. The second SPL of the spintronic device drives the second FGL. The spintronic device further comprises one or more optional thin negative beta material layers, such as layers comprising FeCr, disposed in contact with at least one of the spin kill layers. When electric current is applied, the spin kill layers and optional negative beta material layers eliminate or reduce any spin torque between the FGLs and the SPLs.

Inventors

• Muhammad Asif Bashir
• Alexander GONCHAROV
• Zhigang Bai
• Masato Shiimoto
• Yunfei Ding

Assignees

• WESTERN DIGITAL TECHNOLOGIES, INC.

Dates

Publication Date

20260505

Application Date

20241126

Claims (20)

1. 1 . A magnetic recording head comprising: a shield; a main pole; and a spintronic device disposed between the shield and the main pole, the spintronic device comprising: a first spin kill layer; a first spin polarization layer; a first field generation layer; a first negative beta material layer; a second spin kill layer; a second spin polarization layer; and a second field generation layer, wherein the second field generation layer is disposed over the main pole, the second spin polarization layer is disposed over the second field generation layer, the second spin kill layer is disposed over the second spin polarization layer, the first negative beta material layer is disposed in contact with the second spin kill layer, the first field generation layer is disposed over the first negative beta material layer, the first spin polarization layer is disposed over the first field generation layer, and the first spin kill layer is disposed over the first spin polarization layer.
2. 2 . The magnetic recording head of claim 1 , wherein the spintronic device further comprises a second negative beta material layer disposed between and in contact with the second spin polarization layer and the second spin kill layer.
3. 3 . The magnetic recording head of claim 2 , wherein the spintronic device further comprises a third negative beta material layer disposed in contact with the first spin kill layer.
4. 4 . The magnetic recording head of claim 3 , wherein the spintronic device further comprises a fourth negative beta material layer disposed between the first spin kill layer and the first spin polarization layer.
5. 5 . The magnetic recording head of claim 4 , wherein the first, second, third, and fourth negative beta material layers each individually comprises FeCr and has a thickness of about 1 nm.
6. 6 . The magnetic recording head of claim 1 , wherein the spintronic device further comprises: a first spacer layer disposed between and in contact with the first spin polarization layer and the first field generation layer; a second spacer layer disposed between and in contact with the second field generation layer and the second spin polarization layer; and a third spacer layer disposed between the second field generation layer and the main pole.
7. 7 . The magnetic recording head of claim 1 , wherein the first and second spin kill layers each comprises a non-magnetic material having a resistivity greater than about 100 nano-Ohm·m.
8. 8 . A magnetic recording device comprising the magnetic recording head of claim 1 , the magnetic recording device configured to flow a current from the shield through the spintronic device to the main pole.
9. 9 . A magnetic recording head comprising: a shield; a main pole; and a spintronic device disposed between the shield and the main pole, the spintronic device comprising: a first field generation layer disposed adjacent to the main pole; a first spin polarization layer disposed over the first field generation layer; a first spin kill layer disposed over the first spin polarization layer; a second field generation layer disposed over the first spin kill layer; a second spin polarization layer disposed over the second field generation layer; a second spin kill layer disposed between the second spin polarization layer and the shield; and one or more negative beta material layers disposed between the main pole and the shield.
10. 10 . The magnetic recording head of claim 9 , wherein the second spin kill layer is disposed in contact with the shield.
11. 11 . The magnetic recording head of claim 9 , wherein the second spin kill layer is disposed in contact with the second spin polarization layer.
12. 12 . The magnetic recording head of claim 9 , wherein a first negative beta material layer of the one or more negative beta material layers is disposed between the first spin kill layer and the second field generation layer.
13. 13 . The magnetic recording head of claim 9 , wherein each of the one or more negative beta material layers is disposed in contact with either the first spin kill layer or the second spin kill layer.
14. 14 . A magnetic recording device comprising the magnetic recording head of claim 9 , the magnetic recording device configured to flow a current from the shield through the spintronic device to the main pole.
15. 15 . A magnetic recording device, comprising: a magnetic recording head, the magnetic recording head comprising: a shield; a main pole; and a spintronic device disposed between the shield and the main pole, the spintronic device comprising: a first field generation layer disposed adjacent to the main pole; a first spin polarization layer disposed over the first field generation layer; a first spin kill layer disposed over the first spin polarization layer; a second field generation layer disposed over the first spin kill layer; a second spin polarization layer disposed over the second field generation layer; a second spin kill layer disposed between the second spin polarization layer and the shield; and one or more negative beta material layers disposed between the first spin polarization layer and the shield; and means for flowing a current from the shield through the spintronic device to the main pole.
16. 16 . The magnetic recording device of claim 15 , wherein the first and second spin kill layers each comprises a non-magnetic material having a resistivity greater than about 100 nano-Ohm·m.
17. 17 . The magnetic recording device of claim 15 , wherein each of the one or more negative beta material layers is disposed in contact with either the first spin kill layer or the second spin kill layer.
18. 18 . The magnetic recording device of claim 15 , wherein a first negative beta material layer of the one or more negative beta material layers is disposed between the first spin kill layer and the second field generation layer, and wherein a second negative beta material layer of the one or more negative beta material layers is disposed between the first spin kill layer and the first spin polarization layer.
19. 19 . The magnetic recording device of claim 18 , wherein a third negative beta material layer of the one or more negative beta material layers is disposed between the second spin kill layer and the shield, and wherein a fourth negative beta material layer of the one or more negative beta material layers is disposed between the second spin kill layer and the second spin polarization layer.
20. 20 . The magnetic recording device of claim 15 , wherein the one or more negative beta material layers each individually comprises FeCr and has a thickness of about 1 nm.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisional of co-pending U.S. patent application Ser. No. 18/226,111, filed Jul. 25, 2023, which claims benefit of U.S. provisional patent application Ser. No. 63/421,487, filed Nov. 1, 2022, both of which are herein incorporated by reference. BACKGROUND OF THE DISCLOSURE Field of the Disclosure Embodiments of the present disclosure generally relate to a magnetic recording head comprising a spintronic device, such as a write head of a data storage device, for example a magnetic media drive. Description of the Related Art Over the past few years, various magnetic recording methods have been studied to improve the areal density of a magnetic media device, such as a hard disk drive (HDD). Magnetic recording heads, or write heads, in HDDs can have a significant effect on the overall performance and reliability of the recording device. Magnetic recording heads may be designed to achieve specific advantages, such as improved performance, but may consequently have a negative impact on other characteristics, such as decreased reliability. For example, microwave-assisted magnetic recording (MAMR) is one type of energy-assisted recording technology to improve the recording density of a magnetic recording medium, such as a HDD. In MAMR, a spin torque oscillator (STO) device or a spintronic device is located next to or near the write element such that in operation the STO enhances the write field of the write pole. In addition, the STO produces a high-frequency AC field, such as in a microwave frequency band, that reduces an effective coercivity of a magnetic recording medium used to store data and allows writing of the magnetic recording medium at lower magnetic writing fields emanated from the write pole. Thus, higher recording density of the magnetic recording medium may be achieved by MAMR technology. However, in order to enhance the AC field produced in such STO or spintronic devices, the thickness of various layers within the STO devices need to be increased, such as field generation layers (FGLs). Increasing the thickness of FGLs also increases the perpendicular AC component (Hpac) when writing data, which negatively impacts the overall recording device and causes unwanted cross-talk or spin torque to be generated. Therefore, there is a need in the art for an improved STO or spintronic device configured to enhance the produced AC field without also increasing the perpendicular AC component. SUMMARY OF THE DISCLOSURE The present disclosure is generally related to a magnetic recording device comprising a magnetic recording head. The magnetic recording head comprises a main pole, a shield, and a spintronic device disposed between the main pole and the shield. The spintronic device comprises two field generation layers (FGLs), two spin polarization layers (SPLs), and two spin kill layers. The second SPL of the spintronic device drives the second FGL. The spintronic device further comprises one or more optional thin negative beta material layers, such as layers comprising FeCr, disposed in contact with at least one of the spin kill layers. When electric current is applied, the spin kill layers and optional negative beta material layers eliminate or reduce any spin torque between the FGLs and the SPLs. In one embodiment, a magnetic recording device comprises a magnetic recording head. The magnetic recording head comprises a main pole, a shield, and a spintronic device disposed between the main pole and the shield. The spintronic device comprises a first spin kill layer, a first spin polarization layer, a first field generation layer, a first negative beta material layer, a second spin kill layer, a second spin polarization layer, and a second field generation layer, wherein the second field generation layer is disposed over the main pole, the second spin polarization layer is disposed over the second field generation layer, the second spin kill layer is disposed on the second spin polarization layer, the first negative beta material layer is disposed in contact with the second spin kill layer, the first field generation layer is disposed over the first negative beta material layer, the first spin polarization layer is disposed over the first field generation layer, and the first spin kill layer is disposed over the first spin polarization layer. In another embodiment, a magnetic recording device comprises a magnetic recording head. The magnetic recording head comprises a main pole, a shield, and a spintronic device disposed between the main pole and the shield. The spintronic device comprises a first spin kill layer disposed on the main pole, a first spin polarization layer disposed on the first spin kill layer, a first field generation layer disposed over the first spin polarization layer, a second spin kill layer disposed on the first field generation layer, a second spin polarization layer disposed on the second spin kill layer; and a second field genera