# US 10,762,925 B2 · Magnetic graphene

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- Number: US 10,762,925 B2
- Document ID: US10762925B2
- Status: Granted
- Kind: B2
- Application number: 16/156,934
- Filed: 2018-10-10
- Published: 2019-03-21
- Granted: 2020-09-01
- Earliest claimed: 2014-11-14
- Assignees: The Government of the United States of America, as represented by the Secretary of the Navy
- Applicants: The Government of the United States of America, as represented by the Secretary of the Navy
- Inventors: Woo K. Lee; Keith E. Whitener; Paul E. Sheehan
- Web page: https://patentgrep.com/patent/US10762925B2

## CPC

- G11B 5/84: Processes or apparatus specially adapted for manufacturing record carriers
- B05D 5/00: Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
- C01B 32/184: Preparation
- G11B 5/657: {containing inorganic, non-oxide compound of Si, N, P, B, H or C, e.g. in metal alloy or compound (containing oxygen G11B5/658)}
- H01F 1/42: of organic or organo-metallic materials {, e.g. graphene}(H01F1/44 takes precedence)
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)
- B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02)
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES

## Abstract

A patterned magnetic graphene made from the steps of transferring or growing a graphene film on a substrate, functionalizing the graphene film, hydrogenating the graphene film and forming fully hydrogenated graphene, manipulating the extent of the hydrogen content by using an electron beam from a scanning electron microscope to selectively remove hydrogen, wherein the step of selectively removing hydrogen occurs under a vacuum, and forming areas of magnetic graphene and non-magnetic graphene. A ferromagnetic graphene film comprising film that has a thickness of less than two atom layers thick.

## Claims

### Claim 1

A patterned magnetic graphene made from the steps of:
transferring or growing a graphene film on a substrate; functionalizing the graphene film;
hydrogenating the graphene film and forming fully hydrogenated graphene; manipulating the extent of the hydrogen content by using an electron beam from a scanning electron microscope to selectively remove hydrogen, wherein the step of selectively removing hydrogen occurs under a vacuum; and
forming areas of magnetic graphene and non-magnetic graphene.

### Claim 2 (depends on 1)

The patterned magnetic graphene of claim 1, wherein the step of forming areas of magnetic graphene and non-magnetic graphene comprise the steps of forming an area of fully hydrogenated graphene, forming an area of partially hydrogenated graphene, and forming an area of graphene.

### Claim 3 (depends on 2)

The patterned magnetic graphene of claim 2, wherein the area of highly hydrogenated graphene is non-magnetic and the area of graphene is non-magnetic and the area of partially hydrogenated graphene is magnetic.

### Claim 4 (depends on 1)

The patterned magnetic graphene of claim 1 wherein the step of manipulating the extent of the hydrogen content comprises using heat or pressure.

### Claim 5 (depends on 1)

The patterned magnetic graphene of claim 1 wherein the step of hydrogenating the graphene film comprises reacting the graphene film with anhydrous liquid ammonia and lithium.

### Claim 6 (depends on 5)

The patterned magnetic graphene of claim 5 wherein the graphene film reacts with the anhydrous liquid ammonia and lithium for about 5 to about 2 minutes.

### Claim 7

A uniform ferromagnetic graphene film comprising film that has a thickness of less than two atom layers thick wherein the graphene film is patterned by locally controlling the extent of hydrogenation and wherein the pattern is achieved by an electron beam.

### Claim 8 (depends on 7)

The uniform ferromagnetic graphene film of claim 7 wherein the strength of the ferromagnetism is controlled by the extent of the coverage of the hydrogen.