Nogués J, Skumryev V, Sort J, Stoyanov S, Givord D. Shell-driven magnetic stability in core-shell nanoparticles.
PHYSICAL REVIEW LETTERS 2006;
97:157203. [PMID:
17155354 DOI:
10.1103/physrevlett.97.157203]
[Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2006] [Indexed: 05/12/2023]
Abstract
The magnetic properties of ferromagnetic-antiferromagnetic Co-CoO core-shell nanoparticles are investigated as a function of the in-plane coverage density from 3.5% to 15%. The superparamagnetic blocking temperature, the coercivity, and the bias field radically increase with increasing coverage. This behavior cannot be attributed to the overall interactions between cores. Rather, it can be semiquantitatively understood by assuming that the shells of isolated core-shell nanoparticles have strongly degraded magnetic properties, which are rapidly recovered as nanoparticles come into contact.
Collapse