Abstract
Self-assembly of multicomponent nanocrystal superlattices provides a modular approach to the design of metamaterials by choosing constituent nanocrystal building blocks with desired physical properties and engineering the interparticle coupling. In this work, we report the self-assembly of binary nanocrystal superlattices composed of magnetically hard CoFe2O 4 nanocrystals and magnetically soft Fe3O4 nanocrystals. Both NaZn13- and MgZn2-type CoFe 2O4-Fe3O4 binary nanocrystal superlattices have been formed by the liquid-air interfacial assembly approach. Exchange coupling is achieved in both types of binary superlattices after thermal annealing under vacuum at 400 C. The exchange-coupled CoFe 2O4-Fe3O4 binary nanocrystal superlattices show single-phase magnetization switching behavior and magnetoresistance switching behavior below 200 K. The NaZn13-type CoFe2O4-Fe3O4 binary nanocrystal superlattices annealed at 500 C even exhibit bistable magnetoresistance switching behavior at room temperature constituting a simple nonvolatile memory function.
Original language | English |
---|---|
Pages (from-to) | 1478-1486 |
Number of pages | 9 |
Journal | ACS nano |
Volume | 7 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2013 Feb 26 |
Externally published | Yes |
Keywords
- BNSLs
- binary nanocrystal superlattices
- exchange coupling
- magnetic nanocrystal
- magnetoresistance
- self-assembly
ASJC Scopus subject areas
- Materials Science(all)
- Engineering(all)
- Physics and Astronomy(all)