Ferrimagnetic Heusler compounds with high spin polarization

Patent metadata

Field	Value
Publication number	US-11756578-B2
Application number	US-202117318998-A
Country	US
Kind code	B2
Filing date	May 12, 2021
Priority date	Feb 16, 2021
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

Abstract

A magnetic device and method for providing the magnetic device are disclosed. The magnetic device includes a multilayer structure and a magnetic layer. The multilayer structure includes alternating layers of A and E. A includes a first material. The first material includes at least one of Co, Ru, or Ir. The first material may include an IrCo alloy. E includes at least one other material that includes Al. The other material(s) may include an alloy selected from AlGa, AlSn, AlGe, AlGaGe, AlGaSn, AlGeSn, and AlGaGeSn. A composition of the multilayer structure is represented by A 1-x E x , where x is at least 0.45 and not more than 0.55. The magnetic layer includes an Al-doped Heusler compound. The magnetic layer shares an interface with the multilayer structure.

First claim

What is claimed is:

1. A magnetic device, comprising:
a multilayer structure including alternating layers of A and E, A including a first material, E including at least one other material that includes Al, the first material including at least one of Ru, Ir, or an IrCo alloy, a composition of the multilayer structure being represented by A 1-x E x , where x is at least 0.45 and not more than 0.55; and
a magnetic layer that includes an Al-doped Heusler compound, the magnetic layer sharing an interface with the multilayer structure.

2. The magnetic device of claim 1 , wherein the Al-doped Heusler compound is represented by H 1-y Al y H, where H is an undoped Heusler compound of the Al-doped Heusler compound, H 1-y is the undoped Heusler compound with a species therein reduced by a factor of 1-y, and y is greater than zero and not more than one.

3. The magnetic device of claim 1 , wherein a magnetic moment of the magnetic layer is substantially perpendicular to the interface.

4. The magnetic device of claim 3 , wherein the magnetic layer has a thickness of not more than 5 nm.

5. The magnetic device of claim 1 , wherein the Al-doped Heusler compound includes Al and a Heusler compound, the Heusler compound of the Al-doped Heusler compound is a binary Heusler compound.

6. The magnetic device of claim 5 , wherein the Heusler compound includes at least one of Mn 3.3-z Ge, Mn 3.3-z Sn, or Mn 3.3-y Sb, where z is at least 0 and not more than 0.8 and where y is at least 0 and not more than 1.3.

7. The magnetic device of claim 1 , wherein the first material includes an IrCo alloy.

8. The magnetic device of claim 1 , wherein the at least one other material includes an alloy selected from AlGa, AlSn, AlGe, AlGaGe, AlGaSn, AlGeSn, and AlGaGeSn.

9. The magnetic device of claim 1 , further comprising:
a layer underlying the multilayer structure, the layer including at least one of a Mn y N layer or a V z N layer, where y is at least two and not more than five and z is at least 0.7 and not 10 more than 1.3.

10. The device of claim 9 , wherein the device is a racetrack memory device.

11. The magnetic device of claim 9 , further comprising:
a tunnel barrier; and
an additional magnetic layer in contact with the tunnel barrier, the tunnel barrier being between the magnetic layer and the additional magnetic layer.

12. The magnetic device of claim 11 , wherein the tunnel barrier is selected from MgO or Mg 1-z Al 2+(2/3)z O 4 , wherein −0.5≤z≤0.5.

13. A device, comprising:
a plurality of magnetic junctions, each of the plurality of magnetic junctions including a multilayer structure, a magnetic layer, an additional magnetic layer, and tunnel barrier between the magnetic layer and the additional magnetic layer, the multilayer structure including alternating layers of A and E, A including a first material, E including at least one other material that includes Al, the first material including at least one of Ru, Ir, or an IrCo alloy, a composition of the multilayer structure being represented by A 1-x E x , where x is at least 0.45 and not more than 0.55, the magnetic layer including an Al-doped Heusler compound, the magnetic layer sharing an interface with the multilayer structure, the additional magnetic layer being in contact with the tunnel barrier; and
a plurality of conductive lines coupled with the plurality of magnetic junctions.

14. The device of claim 13 , wherein the Al-doped Heusler compound is represented by H 1-y Al y , where H is an undoped Heusler compound of the Al-doped Heusler compound, H 1-y is the undoped Heusler compound having a species therein reduced by a factor of 1-y, and y is greater than zero and not more than one.

15. The device of claim 13 , wherein a Heusler compound of the Al-doped Heusler compound includes Mn and an element selected from the group consisting of Sn, Sb, or Ge.

16. The device of claim 15 , wherein the Heusler compound includes at least one of Mn 3.3-z Ge, Mn 3.3-z Sn, or Mn 3.3-y Sb, where z is at least 0 and not more than 0.8 and where y is at least 0 and not more than 1.3.

17. The device of claim 14 , wherein each of the plurality of magnetic junctions further includes:
a layer underlying the multilayer structure, the layer including at least one of a Mn y N layer or a V z N layer, where y is at least two and not more than five and z is at least 0.7 and not more than 1.3.

18. A method, comprising:
providing a multilayer structure including alternating layers of A and E, A including a first material, E including at least one other material that includes Al, the first material including at least one of Ru, Ir, or an IrCo alloy, a composition of the multilayer structure being represented by A 1-x E x , where x is at least 0.45 and not more than 0.55; and
providing a magnetic layer on the multilayer structure, the magnetic layer including an Al-doped Heusler compound, the magnetic layer sharing an interface with the multilayer structure.

19. The method of claim 18 , further comprising:
providing a layer interposed including at least one of a Mn y N layer or a V z N layer, the layer underlying the multilayer structure, where y is at least two and not more than five and z is at least 0.7 and not more than 1.3.

20. The method of claim 18 , further comprising:
providing a tunnel barrier; and
providing an additional magnetic layer in contact with the tunnel barrier, the tunnel barrier being between the magnetic layer and the additional magnetic layer.

Assignees

• Samsung Electronics Co Ltd
• IBM

Inventors

• Jeong Jaewoo
• Faleev Sergey
• Filippou Panagiotis Charilaos
• Ferrante Yari
• Parkin Stuart Stephen Papworth
• Samant Mahesh

Classifications

• H01F41/302

  for applying spin-exchange-coupled multilayers, e.g. nanostructured superlattices (spin-exchange-coupled multilayers H01F10/32) · CPC title

• H01F10/324

  Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer · CPC title

• H01F10/30

  characterised by the composition of the intermediate layers {, e.g. seed, buffer, template, diffusion preventing, cap layers (H01F10/06 and H01F10/32 take precedence)} · CPC title

• H01F10/1936

  Half-metallic, e.g. epitaxial CrO2 or NiMnSb films · CPC title

• G11C11/1675

  Writing or programming circuits or methods · CPC title