Magnetically tunable photonic crystals based on anisotropic nanostructures

Patent metadata

Field	Value
Publication number	US-10796849-B2
Application number	US-201615569912-A
Country	US
Kind code	B2
Filing date	Apr 27, 2016
Priority date	Apr 27, 2015
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A method is disclosed of forming magnetically tunable photonic crystals comprising: synthesizing one or more precursory nanoparticles with anisotropic shapes; coating the one or more anisotropic precursory nanoparticles with silica to form composite structures; converting the one or more anisotropic precursory nanoparticles into magnetic nanomaterials through chemical reactions; and assembling the anisotropic magnetic nanoparticles into photonic crystals in a solvent.

First claim

What is claimed is:

1. A method of forming magnetically tunable photonic crystals comprising:
synthesizing precursory nanoparticles with anisotropic shapes, the anisotropic precursory nanoparticles being iron oxyhydroxide (FeOOH) nanorods;
coating the anisotropic precursory nanoparticles with silica to form composite structures;
converting the anisotropic precursory nanoparticles into magnetic nanomaterials through chemical reactions, the chemical reactions including reducing the coated composite structure with reducing agents to render the coated composite structures magnetic; and
assembling the anisotropic magnetic nanoparticles into photonic crystals in a solvent.

2. The method of claim 1 , comprising:
adding tetraethyl orthosilicate into a mixture of distilled water, ethanol, ammonia and anisotropic precursory nanoparticles; and
isolating the coated composite structures by centrifugation.

3. The method of claim 1 , wherein the reducing of the coated composite structure with reducing agents to render the coated composite structures magnetic comprises:
heating the coated composite structures; and
reducing the coated composite structures with the reducing agents to render the coated composite structures magnetic.

4. The method of claim 1 , further comprising:
redispersing the as-reduced magnetic nanoparticles by sonication;
applying a size selection to the magnetic nanoparticles; and
discarding non-dispersible aggregates by centrifugation.

5. The method of claim 1 , comprising:
a solvent for assembling nanoparticles into photonic structures, the solvent being water, ethanol, glycol, and other polar or nonpolar solvents.

6. The method of claim 1 , wherein the synthesizing of the iron oxyhydroxide nanorods comprises:
solution-based synthesis of anisotropic precursory nanoparticles.

7. The method of claim 6 , further comprising:
dissolving iron trichloride in deionized water;
adjusting a concentration of iron cations in the iron trichloride dissolved in the deionized water;
discarding undissolved precipitates after centrifugation from the iron trichloride dissolved in the deionized water to form a supernatant; and
heating the supernatant to form the iron oxyhydroxide nanorods.

8. The method of claim 7 , comprising:
isolating the iron oxyhydroxide nanorods by centrifugation.

9. The method of claim 7 , comprising:
functionalizing a surface of the iron oxyhydroxide nanorods with polyacrylic acid.

Assignees

• Univ California

Inventors

• Yin Yadong
• Wang Mingsheng

Classifications

• B22F1/0547

  Nanofibres or nanotubes · CPC title

• B22F1/0551

  Flake form nanoparticles · CPC title

• H01F41/02 Primary

  for manufacturing cores, coils, or magnets (H01F41/14 takes precedence; for dynamo-electric machines H02K15/00) · CPC title

• H01F1/0036

  showing low dimensional magnetism, i.e. spin rearrangements due to a restriction of dimensions, e.g. showing giant magnetoresistivity, (H01F1/153, H01F1/42 and H01F10/00 take precedence; magnetoresistive sensors G01D5/16, G01R33/06; magnetoresistive recording G11B5/39; magnetic-field-controlled resistors H10N50/10) · CPC title

• C01G49/02 Primary

  Oxides; Hydroxides {(C01G49/0018 takes precedence)} · CPC title