Domain wall moving element, domain wall moving type magnetic recording element and magnetic recording array

Patent metadata

Field	Value
Publication number	US-11894172-B2
Application number	US-201817290118-A
Country	US
Kind code	B2
Filing date	Nov 6, 2018
Priority date	Nov 6, 2018
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

A domain wall moving type magnetic recording element includes: a domain wall moving layer in which first layers containing a rare earth metal and second layers containing a transition metal are alternately stacked in a first direction; and a first electrode and a second electrode which face the domain wall moving layer and are arranged to be away from each other. The domain wall moving layer has SOT suppression parts which are positioned in one of interfaces between the first layers and the second layers and contain a non-magnetic metal. The SOT suppression parts are locally distributed at the interface.

First claim

What is claimed is:

1. A domain wall moving element, comprising:
a domain wall moving layer in which first layers containing a rare earth metal and second layers containing a transition metal are alternately stacked in a first direction; and
a first electrode and a second electrode which face the domain wall moving layer and are arranged to be away from each other,
wherein the domain wall moving layer has spin-orbit torque (SOT) suppression parts which are positioned in one of interfaces between the first layers and the second layers and contain a non-magnetic metal, and
the SOT suppression parts are locally distributed at the interface.

2. The domain wall moving element according to claim 1 , wherein each of the SOT suppression parts contains a non-magnetic transition metal with an atomic number of 48 or less.

3. The domain wall moving element according to claim 1 , wherein the SOT suppression parts are discontinuously distributed at the interface.

4. The domain wall moving element according to claim 3 , wherein the SOT suppression parts are dot-scattered in an island shape at the interface.

5. The domain wall moving element according to claim 1 , wherein each of the SOT suppression parts protrudes from the interface toward the first direction.

6. The domain wall moving element according to claim 1 , wherein the SOT suppression parts are located above a stacked surface of each of the second layers.

7. The domain wall moving element according to claim 6 , wherein the SOT suppression parts are located only above the stacked surface of each of the second layers.

8. The domain wall moving element according to claim 1 , wherein a total area of the SOT suppression parts at one interface is 20% or more of an area of the interface.

9. The domain wall moving element according to claim 1 , wherein each of the first layers contains Tb, Gd or an alloy thereof.

10. A domain wall moving type magnetic recording element, comprising:
the domain wall moving element according to claim 1 ;
a first ferromagnetic layer which faces the domain wall moving layer and is located between the first electrode and the second electrode when viewed in a plan view from the first direction; and
a non-magnetic layer located between the first ferromagnetic layer and the domain wall moving layer.

11. The domain wall moving type magnetic recording element according to claim 10 , wherein some of the SOT suppression parts is located at a position that overlaps the first ferromagnetic layer when viewed in a plan view from the first direction.

12. The domain wall moving type magnetic recording element according to claim 10 , further comprising:
a second ferromagnetic layer between the domain wall moving layer and non-magnetic layer.

13. The domain wall moving type magnetic recording element according to claim 10 , further comprising:
an underlayer on a surface of the domain wall moving layer opposite to a first surface facing the first ferromagnetic layer,
wherein the underlayer is a single layer formed of Ru, Ti, Cu, SiO 2 , MgO, or SiN or a stacked body thereof.

14. A magnetic recording array, comprising:
a plurality of the domain wall moving type magnetic recording elements according to claim 10 .

Assignees

• Tdk Corp

Inventors

• Shinohara Tetsuhito

Classifications

• H10D48/40

  Devices controlled by magnetic fields · CPC title

• H10N50/85

  Materials of the active region · CPC title

• H10B61/00

  Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices · CPC title

• H01F10/3272 Primary

  by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets · CPC title

• H01F10/329 Primary

  Spin-exchange coupled multilayers wherein the magnetisation of the free layer is switched by a spin-polarised current, e.g. spin torque effect · CPC title