Magnetoelectric chromia having increased critical temperature

Patent metadata

Field	Value
Publication number	US-9718700-B2
Application number	US-201514629178-A
Country	US
Kind code	B2
Filing date	Feb 23, 2015
Priority date	Feb 24, 2014
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A magnetoelectric composition of boron and chromia is provided. The boron and chromia alloy can contain boron doping of 1%-10% in place of the oxygen in the chromia. The boron-doped chromia exhibits an increased critical temperature while maintaining magnetoelectric characteristics. The composition can be fabricated by depositing chromia in the presence of borane. The boron substitutes oxygen in the chromia, enhancing the exchange energy and thereby increasing Néel temperature.

First claim

What is claimed is:

1. A magnetoelectric composition comprising:
boron doped chromia.

2. The magnetoelectric composition of claim 1 , wherein a substitution ratio of oxygen atoms of the chromia replaced by the boron is between 1% and 10%.

3. The magnetoelectric composition of claim 1 , wherein a substitution ratio of oxygen atoms of the chromia replaced by the boron is about 3%.

4. The magnetoelectric composition of claim 1 , having a Néel temperature of at least 400 K.

5. A voltage controlled switching device, comprising:
boron doped chromia as an antiferromagnetic material layer, wherein the boron doped chromia comprises between 1% and 10% boron substitution for oxygen in the chromia.

6. The device of claim 5 , wherein the boron doped chromia has a Néel temperature of at least 400 K.

7. The device of claim 5 , wherein the device is a switchable chemical catalyst based device comprising the boron doped chromia positioned such that catalytically responsive reaction gases can be passed over a surface of the boron doped chromia and a voltage source applied to a tip over the boron doped chromia.

8. A method of fabricating a magnetoelectric material having increased critical temperature, the method comprising:
forming a magnetoelectric composition comprising boron doped chromia by depositing chromia in the presence of borane vapor.

9. The method of claim 8 , wherein depositing chromia in the presence of borane vapor comprises performing pulse laser deposition of chromia in the presence of borane vapor.

10. The method of claim 8 , wherein the borane vapor comprises decaborane.

11. The method of claim 8 , wherein the borane vapor comprises pentaborane.

12. The method of claim 8 , wherein the borane vapor comprises diborane.

13. The method of claim 8 , wherein the magnetoelectric composition comprising boron doped chromia is formed with between 1% and 10% boron substitution for oxygen in the chromia.

14. The method of claim 8 , wherein the magnetoelectric composition comprising boron doped chromia is formed with about 3% boron substitution for oxygen in the chromia.

15. The method of claim 8 , wherein the magnetoelectric composition comprising boron doped chromia is formed to have a Néel temperature of at least 400 K.

Assignees

• Univ Nebraska

Inventors

• Binek Christian
• Dowben Peter
• Belashchenko Kirill
• Wysocki Aleksander
• Mu Sai
• Street Mike

Classifications

• H01F10/002

  Antiferromagnetic thin films, i.e. films exhibiting a Néel transition temperature (H01F10/3218 and H01F10/3268 take precedence) · CPC title

• C01G37/027 Primary

  Chromium dioxide · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• C01P2002/50

  Solid solutions · CPC title

• H01F10/3268

  the exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e. so-called spin-valve [SV] structure, e.g. NiFe/Cu/NiFe/FeMn · CPC title