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Title: Bistable Magnetoresistance Switching in Exchange-Coupled CoFe2O4-Fe3O4 Binary Nanocrystal Superlattices by Self-Assembly and Thermal Annealing

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 CoFe2O4 nanocrystals and magnetically soft Fe3O4 nanocrystals. Both NaZn13- and MgZn2-type CoFe2O4-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 degrees C. The exchange-coupled CoFe2O4-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 degrees C even exhibit bistable magnetoresistance switching behavior at room temperature constituting a simple nonvolatile memory function.

Authors:
; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE Advanced Research Projects Agency - Energy (ARPA-E)
OSTI Identifier:
1211204
DOE Contract Number:  
DE-AR0000123
Resource Type:
Journal Article
Journal Name:
ACS Nano
Additional Journal Information:
Journal Volume: 7; Journal Issue: 2; Journal ID: ISSN 1936-0851
Country of Publication:
United States
Language:
English

Citation Formats

Chen, J, Ye, XC, Oh, SJ, Kikkawa, JM, Kagan, CR, and Murray, CB. Bistable Magnetoresistance Switching in Exchange-Coupled CoFe2O4-Fe3O4 Binary Nanocrystal Superlattices by Self-Assembly and Thermal Annealing. United States: N. p., 2013. Web. doi:10.1021/nn3052617.
Chen, J, Ye, XC, Oh, SJ, Kikkawa, JM, Kagan, CR, & Murray, CB. Bistable Magnetoresistance Switching in Exchange-Coupled CoFe2O4-Fe3O4 Binary Nanocrystal Superlattices by Self-Assembly and Thermal Annealing. United States. doi:10.1021/nn3052617.
Chen, J, Ye, XC, Oh, SJ, Kikkawa, JM, Kagan, CR, and Murray, CB. Fri . "Bistable Magnetoresistance Switching in Exchange-Coupled CoFe2O4-Fe3O4 Binary Nanocrystal Superlattices by Self-Assembly and Thermal Annealing". United States. doi:10.1021/nn3052617.
@article{osti_1211204,
title = {Bistable Magnetoresistance Switching in Exchange-Coupled CoFe2O4-Fe3O4 Binary Nanocrystal Superlattices by Self-Assembly and Thermal Annealing},
author = {Chen, J and Ye, XC and Oh, SJ and Kikkawa, JM and Kagan, CR and Murray, CB},
abstractNote = {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 CoFe2O4 nanocrystals and magnetically soft Fe3O4 nanocrystals. Both NaZn13- and MgZn2-type CoFe2O4-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 degrees C. The exchange-coupled CoFe2O4-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 degrees C even exhibit bistable magnetoresistance switching behavior at room temperature constituting a simple nonvolatile memory function.},
doi = {10.1021/nn3052617},
journal = {ACS Nano},
issn = {1936-0851},
number = 2,
volume = 7,
place = {United States},
year = {2013},
month = {2}
}