Multiferroic heterostructures

Patent metadata

Field	Value
Publication number	US-11276728-B2
Application number	US-202016784351-A
Country	US
Kind code	B2
Filing date	Feb 7, 2020
Priority date	Feb 7, 2020
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

A heterostructure includes a substrate exhibiting a piezoelectric effect, and a magnetostrictive film supported by the substrate. The magnetostrictive film includes an iron-gallium alloy. The iron-gallium alloy has a gallium composition greater than 20%.

First claim

What is claimed is:

1. A heterostructure comprising:
a substrate exhibiting a piezoelectric effect; and
a magnetostrictive film supported by the substrate;
wherein the magnetostrictive film comprises an iron-gallium alloy, and wherein the iron-gallium alloy has a gallium composition greater than 20%, and
wherein the iron-gallium alloy is arranged in A2 crystalline phase.

2. The heterostructure of claim 1 , further comprising a buffer layer disposed between the substrate and the magnetostrictive film, wherein the buffer layer comprises iron.

3. The heterostructure of claim 1 , wherein the gallium composition is less than about 30%.

4. The heterostructure of claim 1 , wherein the iron-gallium alloy is single-phase.

5. The heterostructure of claim 1 , wherein the iron-gallium alloy is arranged in single crystalline form.

6. The heterostructure of claim 1 , wherein the substrate comprises a ferroelectric material.

7. The heterostructure of claim 1 , wherein the substrate comprises (1-x)PbMg 1/3 Nb 2/3 O 3 -(x)PbTiO 3 .

8. The heterostructure of claim 1 , wherein the substrate is a uniform, piezoelectric substrate.

9. A device comprising:
a substrate comprising a first surface and a second surface opposite the first surface, the substrate exhibiting a piezoelectric effect;
a conductive element disposed along the first surface of the substrate, the conductive element comprising a magnetostrictive film, the magnetostrictive film being patterned to define a lateral extent of the conductive element; and
a contact disposed along the second surface and positioned in accordance with the lateral extent of the conductive element to define a voltage across the substrate that correlates with a strain along the first surface for coupling to the conductive element;
wherein the magnetostrictive film comprises an iron-gallium alloy, and wherein the iron-gallium alloy has a gallium composition greater than 20%, and
wherein the iron-gallium alloy is single-phase.

10. The device of claim 9 , wherein the conductive element comprises a current channel of a switch arrangement such that the contact is configured to operate as a gate of the switch arrangement.

11. The device of claim 9 , further comprising a voltage source coupled to the conductive element and configured to establish a magnetization resonance condition via the magnetostrictive film.

12. The device of claim 9 , wherein the gallium composition is less than about 30%.

13. The device of claim 9 , wherein the iron-gallium alloy is arranged in single-crystalline, A2 phase.

14. The device of claim 9 , further comprising a buffer layer disposed at the first surface between the substrate and the magnetostrictive film, wherein the buffer layer comprises iron.

15. The device of claim 9 , wherein the substrate is a uniform, piezoelectric substrate.

16. A method of fabricating a heterostructure, the method comprising:
providing a substrate, the substrate exhibiting a piezoelectric effect; and
growing epitaxially a magnetostrictive film, such that the magnetostrictive film is supported by the substrate, the magnetostrictive film comprising an iron-gallium alloy;
wherein growing the magnetostrictive film comprises supplying an iron flux and a gallium flux to the substrate such that the iron-gallium alloy has a gallium composition greater than 20%.

17. The method of claim 16 , further comprising:
patterning the magnetostrictive film via an ion bombardment process, the ion bombardment process damaging an oxide layer of the magnetostrictive film; and
removing the damaged oxide layer of the magnetostrictive film with an acidic solution.

18. The method of claim 16 , further comprising depositing, on the substrate, a buffer layer on which the magnetostrictive film is grown.

19. The method of claim 16 , wherein the gallium composition is less than about 30%.

20. The method of claim 16 , wherein growing the magnetostrictive film is implemented such that the iron-gallium alloy is arranged in single crystalline form.

21. The method of claim 16 , wherein providing the substrate comprises fabricating a composite substrate, the composite substrate comprising a piezoelectric layer.

Assignees

• Univ Michigan Regents
• Univ Cornell

Inventors

• Heron John Thomas
• Meisenheimer Peter Benjamin
• Schlom Darrell G
• Steinhardt Rachel

Classifications

• H10N35/85 Primary

  Magnetostrictive active materials · CPC title

• H01L41/20

  Electricity · mapped topic

• H01L41/1875

  Electricity · mapped topic

• H01L27/20 Primary

  Electricity · mapped topic

• H01L41/09

  Electricity · mapped topic