Layered Heusler alloys and methods for the fabrication and use thereof

Patent metadata

Field	Value
Publication number	US-10403425-B2
Application number	US-201715477486-A
Country	US
Kind code	B2
Filing date	Apr 3, 2017
Priority date	Dec 2, 2015
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

Disclosed herein are layered Heusler alloys. The layered Heusler alloys can comprise a first layer comprising a first Heusler alloy with a face-centered cubic (fcc) crystal structure and a second layer comprising a second Heusler alloy with a fcc crystal structure, the second Heusler alloy being different than the first Heusler alloy, wherein the first layer and the second layer are layered along a layering direction, the layering direction being the [110] or [111] direction of the fcc crystal structure, thereby forming the layered Heusler alloy.

First claim

What is claimed is:

1. A layered Heusler alloy, comprising:
a first layer comprising a first Heusler alloy with a face-centered cubic (fcc) crystal structure;
a second layer comprising a second Heusler alloy with a fcc crystal structure, the second Heusler alloy being different than the first Heusler alloy;
wherein the first layer and the second layer are layered along a layering direction, the layering direction being the [110] or [111] direction of the fcc crystal structure, thereby forming the layered Heusler alloy;
wherein the layered Heusler alloy has a magnetocrystalline anisotropy of greater than 0 J/m 3 along a direction perpendicular to the layering direction;
wherein the layered Heusler alloy comprises a half metal or a near half metal; and
wherein the layered Heusler alloy has a Fermi level and a gapped spin-channel with a gap, and wherein the Fermi level of the layered Heusler alloy falls within the gap of the gapped spin-channel of the layered Heusler alloy.

2. The layered Heusler alloy of claim 1 , wherein:
the layered Heusler alloy is layered along the [110] direction;
the first Heusler alloy has a formula A p BC, wherein:
p is 1 or 2;
A and B are each a transition metal, with the proviso that A and B are not the same transition metal; and
C is an element from Group 13, 14, or 15;

the first layer comprises a first number of sublayers;
the second Heusler alloy has a formula X q YZ, wherein:
q is 1 or 2;
X and Y are each a transition metal, with the proviso that X and Y are not the same transition metal; and
Z is an element from Group 13, 14, or 15;

the second layer comprises a second number of sublayers; and
the first number of sublayers is the same as the second number of sublayers, such that the layered Heusler alloy has a unit cell comprising (A p BC)a(X q YZ)a, wherein a is the first number of sublayers and a is an integer from 1 to 1000.

3. The layered Heusler alloy of claim 2 , wherein:
A and B are selected from the group consisting of: scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, and palladium; and
X and Y are selected from the group consisting of: scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, and palladium.

4. The layered Heusler alloy of claim 2 , wherein:
A and B are selected from the group consisting of: titanium, vanadium, chromium, manganese, iron, cobalt, nickel, rhodium, and palladium; and
X and Y are selected from the group consisting of: titanium, vanadium, chromium, manganese, iron, cobalt, nickel, rhodium, and palladium.

5. The layered Heusler alloy of claim 2 , wherein C and Z are independently selected from the group consisting of: boron, aluminum, gallium, indium, thallium, carbon, silicon, germanium, tin, lead, nitrogen, phosphorous, arsenic, antimony, and bismuth.

6. The layered Heusler alloy of claim 2 , wherein C and Z are independently selected from the group consisting of: aluminum, gallium, silicon, germanium, tin, phosphorous, arsenic, and antimony.

7. The layered Heusler alloy of claim 1 , wherein
the layered Heusler alloy is layered along the [111] direction;
the first Heusler alloy has a formula A p BC, wherein:
p is 1 or 2;
A and B are each a transition metal, with the proviso that A and B are not the same transition metal; and
C is an element from Group 13, 14, or 15;

the first layer comprises a first number of sublayers, the first number of sublayers being 4, 6, or 8;
the second Heusler alloy has a formula X q YZ, wherein:
q is 1 or 2;
X and Y are each a transition metal, with the proviso that X and Y are not the same transition metal; and
Z is an element from Group 13, 14, or 15;

the second layer comprises a second number of sublayers, the second number of sublayers being 4, 6, or 8; and
the sum of the first number of sublayers and second number of sublayers is 12, such that:
when the first number of sublayers is 4, the layered Heusler alloy has a unit cell comprising (A p BC)(X q YZ) 2 , wherein p and q are independently 1 or 2;
when the first number of sublayers is 8, the layered Heusler alloy has a unit cell comprising (A p BC) 2 (X q YZ), wherein p and q are independently 1 or 2; and
when the first number of sublayers is 6, the layered Heusler alloy has a unit cell comprising (A p BC)(A p-1 XBZ)(X q YZ), wherein p and q are independently 1 or 2.

8. The layered Heusler alloy of claim 7 , wherein:
A and B are selected from the group consisting of: scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, and palladium; and
X and Y are selected from the group consisting of: scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, and palladium.

9. The layered Heusler alloy of claim 7 , wherein:
A and B are selected from the group consisting of: titanium, vanadium, chromium, manganese, iron, cobalt, nickel, rhodium, and palladium; and
X and Y are selected from the group consisting of: titanium, vanadium, chromium, manganese, iron, cobalt, nickel, rhodium, and palladium.

10. The layered Heusler alloy of claim 7 , wherein C and Z are independently selected from the group consisting of: boron, aluminum, gallium, indium, thallium, carbon, silicon, germanium, tin, lead, nitrogen, phosphorous, arsenic, antimony, and bismuth.

11. The layered Heusler alloy of claim 7 , wherein C and Z are independently selected from the group consisting of: aluminum, gallium, silicon, germanium, tin, phosphorous, arsenic, and antimony.

12. The layered Heusler alloy of claim 1 , wherein the first Heusler alloy and the second Heusler alloy are selected from the group consisting of Co 2 CrSi, Co 2 CrSb, Co 2 FeSi, Co 2 MnAl, Co 2 MnSi, Co 2 MnSb, Co 2 TiGe, Co 2 VGa, Co 2 VSn, Fe 2 MnAl, Fe 2 MnGa, Fe 2 MnSi, Fe 2 TiGe, Fe 2 TiSi, CoMnP, CoTiP, RhFeGe, RuMnAs, NiMnP, NiMnSi, NiMnAs, NiMnSb, NiVSb, CoMnSb, and CoTiSi.

13. The layered Heusler alloy of claim 1 , wherein the first Heusler alloy comprises a half metal or a near half metal.

14. The layered Heusler alloy of claim 1 , wherein the second Heusler alloy comprises a half metal or a near half metal.

15. The layered Heusler alloy of claim 1 , wherein the magnetocrystalline anisotropy of the layered Heusler alloy along a direction perpendicular to the layering direction is from greater than 0 J/m 3 to 10 6 J/m 3 .

16. The layered Heusler alloy of claim 1 , wherein the μ 0 H eff of the layered Heusler alloy is from −10 to 10 10 N A −1 m −1 .

17. The layered Heusler alloy of claim 1 , wherein the layered Heusler alloy has a μ 0 H eff of greater than 0 N A −1 m −1 .

18. The layered Heusler alloy of claim 1 , wherein the layered Heusler alloy further comprises:
a third layer comprising a third Heusler alloy with a fcc crystal structure, the third Heusler alloy being different than the first Heusler alloy, the second Heusler alloy, or combinations thereof; and
the first layer, the second layer, and the third layer are layered along the layering direction.

Assignees

• Univ Alabama

Inventors

• Butler William H
• Munira Kamaram
• Azadani Javad Ghasemi

Classifications

• C22C38/02

  containing silicon · CPC title

• H01F10/145

  containing Al, e.g. SENDUST · CPC title

• H01F10/14

  containing iron or nickel ({H01F10/126} , H01F10/13, H01F10/16 take precedence) · CPC title

• C22C19/07

  based on cobalt · CPC title

• C22C19/03

  based on nickel · CPC title