Low magnetic flux density interface layer for spin torque oscillator

Patent metadata

Field	Value
Publication number	US-10037772-B2
Application number	US-201715714992-A
Country	US
Kind code	B2
Filing date	Sep 25, 2017
Priority date	Jun 28, 2016
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

A magnetic field-assisted magnetic recording (MAMR) head is provided, which includes a recording main pole, a seed layer, and a spin torque oscillator (STO) positioned over the main pole, in this order, in a stacking direction from a leading side to a trailing side of the recording head. The STO comprises a spin polarized layer (SPL), an interlayer with fcc structure, and a field generating layer (FGL), in this order in the stacking direction. The FGL comprises a low magnetic flux density interface (LMFDI) layer with bcc structure that directly contacts the interlayer.

First claim

The invention claimed is:

1. A spin torque device comprising:
a seed layer and a spin torque oscillator (STO) positioned over a substrate, in this order;
wherein:
the STO comprises a spin polarized layer (SPL), an interlayer with fcc structure, and a field generating layer (FGL), in this order; and
the FGL comprises at least three different magnetic materials, including a low magnetic flux density interface (LMFDI) layer with bcc structure that directly contacts the interlayer.

2. The spin torque device of claim 1 , wherein the LMFDI layer comprises an alloy X-Y-Z comprising element X, element Y, and element Z, wherein:
X is selected from a group consisting of Co and Fe;
Y is selected from a group consisting of Cr, Mn, Fe, and Co; and
Z is Al.

3. The spin torque device of claim 1 , wherein the LMFDI layer comprises an alloy of Co—Fe—Al.

4. The spin torque device of claim 1 , wherein the LMFDI layer has a thickness of 7.5 to 10 Å.

5. The spin torque device of claim 1 , wherein the FGL further comprises a Heusler layer directly contacting the LMFDI layer, the Heusler layer comprising a different material from the LMFDI layer, and the Heusler layer further comprising a magnetically unresponsive magnetic dead layer that directly contacts the LMFDI layer.

6. The spin torque device of claim 5 , wherein the magnetic dead layer has a thickness of less than 5 Å.

7. The spin torque device of claim 5 , wherein the Heusler layer comprises an alloy X-Y-Z comprising element X, element Y, and element Z, wherein:
X is selected from a group consisting of Co and Fe,
Y is selected from a group consisting of Cr, Mn, Fe, and Co, and
Z is selected from a group consisting of Si and Ge.

8. The spin torque device of claim 7 , wherein the Heusler layer comprises an alloy of Co—Mn—Ge.

9. The spin torque device of claim 1 , wherein the seed layer comprises a bcc layer positioned above an hcp layer or an fcc layer.

10. The spin torque device of claim 1 , wherein the FGL comprises the LMFDI layer, a Heusler layer directly contacting the LMFDI layer, and a CoFe layer directly contacting the Heusler layer.

11. The spin torque device of claim 1 , wherein the LMFDI layer comprises an alloy of Co—Mn—Al.

12. A spin torque device comprising:
a seed layer and a spin torque oscillator (STO) positioned over a substrate, in this order;
wherein:
the STO comprises a field generating layer (FGL), an interlayer with fcc structure, and a spin polarized layer (SPL), in this order; and
the SPL comprises a LMFDI layer with bcc structure that directly contacts the interlayer.

13. The spin torque device of claim 12 , wherein the LMFDI layer comprises an alloy X-Y-Z comprising element X, element Y, and element Z, wherein:
X is selected from a group consisting of Co and Fe,
Y is selected from a group consisting of Cr, Mn, Fe, and Co, and
Z is Al.

14. The spin torque device of claim 13 , wherein the LMFDI layer comprises an alloy of Co—Fe—Al or an alloy of Co—Mn—Al.

15. The spin torque device of claim 12 , wherein the LMFDI layer has a thickness of 7.5 to 10 Å.

16. The spin torque device of claim 12 , wherein the SPL further comprises a Heusler layer directly contacting the LMFDI layer, the Heusler layer comprising a different material from the LMFDI layer, and the Heusler layer further comprising a magnetically unresponsive magnetic dead layer that directly contacts the LMFDI layer.

17. The spin torque device of claim 16 , wherein the magnetic dead layer has a thickness of less than 5 Å.

18. The spin torque device of claim 16 , wherein the Heusler layer comprises an alloy X-Y-Z comprising element X, element Y, and element Z, wherein:
X is selected from a group consisting of Co and Fe,
Y is selected from a group consisting of Cr, Mn, Fe, and Co, and
Z is selected from a group consisting of Si and Ge.

19. The spin torque device of claim 18 , wherein the Heusler layer comprises an alloy of Co—Mn—Ge.

20. The spin torque device of claim 12 , wherein the seed layer comprises a bcc layer positioned above an hcp layer or an fcc layer.

Assignees

• Western Digital Tech Inc

Inventors

• Okamura Susumu
• Sato Masashige
• Nagasaka Keiichi
• Sato Yo

Classifications

• G11B5/3153 Primary

  including at least one magnetic thin film coupled by interfacing to the basic magnetic thin film structure · CPC title

• G11B2005/0024

  Microwave assisted recording · CPC title

• G11B5/147

  with cores being composed of metal sheets, i.e. laminated cores {with cores composed of isolated magnetic layers, e.g. sheets (in thin films G11B5/31)} · CPC title

• G11B5/3146

  magnetic layers · CPC title

• G11B5/235

  Selection of material for gap filler {(G11B5/232 takes precedence)} · CPC title