Increased surface spin stability in γ-Fe2O3 nanoparticles with a Cu shell

R D Desautels; E Skoropata; Y-Y Chen; H Ouyang; J W Freeland; J van Lierop

doi:10.1088/0953-8984/24/14/146001

Increased surface spin stability in γ-Fe2O3 nanoparticles with a Cu shell

J Phys Condens Matter. 2012 Apr 11;24(14):146001. doi: 10.1088/0953-8984/24/14/146001. Epub 2012 Mar 13.

Authors

R D Desautels¹, E Skoropata, Y-Y Chen, H Ouyang, J W Freeland, J van Lierop

Affiliation

¹ Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.

PMID: 22410936
DOI: 10.1088/0953-8984/24/14/146001

Abstract

γ-Fe(2)O(3) nanoparticles were coated with a Cu shell in situ during synthesis. An interfacial monolayer of CuO in the Cu-coated γ-Fe(2)O(3) nanoparticles was discovered that stabilized the disordered surface spins of γ-Fe(2)O(3) nanoparticles. Element-specific x-ray absorption spectroscopy at the L-edges for Cu and Fe indicated the magnetic moment of the Cu in the shell interacted with the γ-Fe(2)O(3) nanoparticle's surface magnetic moments. This exchange interaction between the Fe and Cu at the interface permitted an overall Cu moment in CuO (an antiferromagnet typically) that altered the γ-Fe(2)O(3) nanomagnetism. Increasing the Cu shell thickness also increased the total Fe magnetism of the nanoparticles.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Copper / chemistry*
Ferric Compounds / chemistry*
Magnetics*
Metal Nanoparticles / chemistry*
Nanotechnology
Particle Size
Surface Properties
X-Ray Absorption Spectroscopy

Substances

Ferric Compounds
Copper
cupric oxide