# US 9,437,222 B1 · Spin torque oscillator with high spin torque efficiency and reliability

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- Number: US 9,437,222 B1
- Document ID: US9437222B1
- Status: Granted
- Kind: B1
- Application number: 14/726,513
- Filed: 2015-05-30
- Granted: 2016-09-06
- Earliest claimed: 2015-05-30
- Assignees: HGST Netherlands B.V.
- Applicants: HGST Netherlands B.V.
- Inventors: Susumu Okamura; Masao Shiimoto; Katsuro Watanabe; Masashige Sato; Keiichi Nagasaka; Yo Sato; Masukazu Igarashi
- Web page: https://patentgrep.com/patent/US9437222B1

## CPC

- G11B 5/3146: {magnetic layers}
- G11B 5/1278: {specially adapted for magnetisations perpendicular to the surface of the record carrier}
- G11B 5/235: Selection of material for gap filler {(G11B5/232 takes precedence)}
- H03B 15/006: {using spin transfer effects or giant magnetoresistance}
- G11B 5/314: {where the layers are extra layers normally not provided in the transducing structure, e.g. optical layers (G11B5/3196 takes precedence)}
- G11B 2005/0024: {Microwave assisted recording}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)
- H03B: GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS (generators adapted for electrophonic musical instruments G10H; masers or lasers H01S; generation of oscillations in plasma H05H)

## Abstract

A magnetic oscillator for use in Microwave Assisted Magnetic Recording (MAMR). The magnetic oscillator can be a spin torque oscillator and includes a magnetic spin polarization layer, a magnetic field generation layer and a non-magnetic intermediate layer sandwiched between the magnetic spin polarization layer and the magnetic field generation layer. The non-magnetic intermediate layer is constructed of a material that provides improved performance, increased lifespan and thermal robustness. The magnetic intermediate layer is constructed of an alloy of Ag and an element X. More preferably the element X can be Sn or Zn.

## Claims

### Claim 1

A magnetic oscillator, comprising:
a magnetic spin polarization layer;
a magnetic field generation layer; and
a nonmagnetic intermediate layer between the magnetic spin polarization layer and the magnetic field generation layer, the nonmagnetic intermediate layer comprising an Alloy of Ag and Zn.

### Claim 2 (depends on 1)

The magnetic oscillator as in claim 1, wherein the intermediate layer comprises Ag—Zn having 5-50 atomic percent Zn.

### Claim 3 (depends on 1)

The magnetic oscillator as in claim 1, wherein the magnetic oscillator is formed on and electrically connected with a magnetic write pole.

### Claim 4

A magnetic write element, comprising:
a magnetic write pole;
a trailing magnetic shield; and
a magnetic oscillator located between and contacting the magnetic write pole and the magnetic trailing shield, the magnetic oscillator further comprising:
a magnetic spin polarization layer;
a magnetic field generation layer; and
a nonmagnetic intermediate layer between the magnetic spin polarization layer and the magnetic field generation layer, the nonmagnetic intermediate layer comprising an Alloy of Ag and an element X, where X is selected from the group consisting of Zn and Sn.

### Claim 5 (depends on 4)

The magnetic write element as in claim 4, wherein the intermediate layer comprises Ag—Zn having 5-50 atomic percent Zn.

### Claim 6 (depends on 4)

The magnetic write element as in claim 4, wherein the intermediate layer comprises Ag—Sn having 3-13 atomic percent Sn.

### Claim 7 (depends on 4)

The magnetic write element as in claim 4, further comprising a magnetic return pole that is magnetically connected with the magnetic write pole in a region removed from a media facing surface.

### Claim 8 (depends on 4)

The magnetic write element as in claim 4 further comprising circuitry connected with the magnetic write pole and the magnetic trailing shield for supplying an electrical current through the magnetic oscillator.

### Claim 9 (depends on 4)

The magnetic write element as in claim 4 wherein the magnetic oscillator is a spin torque oscillator.

### Claim 10

A magnetic data recording system, comprising:
a housing;
a magnetic media held within the housing;
an actuator held within the housing;
a slider connected with the actuator for movement adjacent to a surface of the magnetic media; and
a write element formed on the slider, the write element further comprising:
a magnetic write pole;
a trailing magnetic shield; and
a magnetic oscillator located between and contacting the magnetic write pole and the magnetic trailing shield, the magnetic oscillator further comprising:
a magnetic spin polarization layer;
a magnetic field generation layer; and
a nonmagnetic intermediate layer between the magnetic spin polarization layer and the magnetic field generation layer, the nonmagnetic intermediate layer comprising an Alloy of Ag and an element X where X is selected from the group consisting of Zn and Sn.

### Claim 11 (depends on 10)

The magnetic data recording system as in claim 10, wherein the intermediate layer comprises Ag—Zn having 5-50 atomic percent Zn.

### Claim 12 (depends on 10)

The magnetic data recording system as in claim 10, wherein the intermediate layer comprises Ag—Sn having 3-13 atomic percent Sn.

### Claim 13 (depends on 10)

The magnetic data recording system as in claim 10, wherein the write element further comprises circuitry connected with the magnetic write pole and the magnetic trailing shield for supplying an electrical current through the magnetic oscillator.