Claims
- 1. An article comprising a magnetoresistive material that comprises CrO2 powders fixed in a position in which the CrO2 powders are aligned in the same direction in a magnetic field.
- 2. The article of claim 1, wherein the CrO2 powders are fixed to a substrate by evaporating the an organic solvent.
- 3. The article of claim 1, wherein the CrO2 powders have a Cr2O3 insulating surface layer of thickness of about 1-3 nm.
- 4. The article of claim 1, wherein the magnetoresistance ratio is at least 10%, at a temperature of 5 degrees Kelvin and a magnetic field of 1000 Oersted.
- 5. The article of claim 4, wherein the magnetoresistance ratio is at least 20%, at a temperature of 5 degrees Kelvin and a magnetic field of 1000 Oersted.
- 6. The article of claim 1, wherein the magnetoresistive material is disposed in the article as a layer having a thickness of about 1 nm to about 100 mm.
- 7. The article of claim 1, wherein the magnetoresistive material comprises one, two or more CrO2 grains having an average grain size of about 10 nm to about 50 mm.
- 8. An article comprising a magnetoresistive structure that comprises a first layer consisting essentially of CrO2 particles aligned in a magnetic field, a second layer consisting essentially of Cr2O3, and a third layer consisting essentially of CrO2 or other magnetic conductors.
- 9. The article of claim 8, wherein the CrO2 in the first and/or third layers is single crystal CrO2.
- 10. The invention of claim 8, wherein the magnetoresistive material exhibits a magnetoresistance ratio greater than 20%, at a temperature of 5 degrees Kelvin and a magnetic field of 1000 Oersted.
- 11. The invention of claim 8, wherein the magnetoresistive material exhibits a magnetoresistance ratio greater than 30%, at a temperature of 5 degrees Kelvin and a magnetic field of 1000 Oersted.
- 12. The invention of claim 8, wherein the magnetoresistive material exhibits a magnetoresistance ratio greater than 40%, at a temperature of 5 degrees Kelvin and a magnetic field of 1000 Oersted.
- 13. The invention of claim 8, wherein the magnetoresistive material is used in magnetic random access memory (MRAM), such as MRAM for computers.
- 14. The invention of claim 8, wherein the magnetoresistive material is used in a magnetic field sensor.
- 15. The invention of claim 8, wherein the magnetoresistive material is used in a spin-transistor.
- 16. A method for making an article that comprises a magnetoresistive material, comprising the steps of:aligning CrO2 particles in the same direction in a magnetic field; and fixing the CrO2 particles in a layer.
- 17. The method of claim 16, wherein the CrO2 layer has a thickness of about 1 nm to about 100 mm.
- 18. The method of claim 16, wherein the magnetoresistive material exhibits a magnetoresistance ratio greater than 10%, at a temperature of 5 degrees Kelvin and a magnetic field of 1000 Oersted.
- 19. The method of claim 16, wherein the CrO2 has an average grain size of about 10 nm to about 50 mm.
CROSS-REFERENCE TO RELATED APPLICATIONS
Priority of U.S. Provisional Patent Application Ser. No. 60/226,638, filed Aug. 21, 2000, incorporated herein by reference, is hereby claimed.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made in the performance of work under DoD/DARPA Grant No. MDA972-97-1-0003 through AMRI/UNO. The government may have rights in this invention.
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Provisional Applications (1)
|
Number |
Date |
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|
60/226638 |
Aug 2000 |
US |