Modulation of Magnetic Heating via Dipolar Magnetic Interactions in Monodisperse and Crystalline Iron Oxide Nanoparticles

Salas, Gorka; Camarero, Julio; Cabrera, David; Takacs, Hélène; Varela, María; Ludwig, Robert; Dähring, Heidi; Hilger, Ingrid; Miranda, Rodolfo; Morales, María del Puerto; Teran, Francisco José

Abstract

In the pursuit of controlling the heat exposure mediated by magnetic nanoparticles, we provide new guidelines for tailoring magnetic relaxation processes via dipolar interactions. For this purpose, highly crystalline and monodisperse magnetic iron oxide nanocrystals whose sizes range from 7 to 22 nm were synthesized by thermal decomposition of iron organic precursors in 1-octadecene. The as-synthesized nanoparticles are soft nanomagnets, showing superparamagnetic-like behavior and SAR values which progressively increase with particle size, field frequency, and amplitude up to 3.6 kW/gFe. Our data show the influence of media viscosity, particle size, and concentration on dipolar interactions and consequently on the magnetic relaxation processes related to the heat release. Understanding the role of dipolar interactions is of great importance toward the use of iron oxide nanoparticles as efficient hyperthermia mediators.

• Journal Article Type: Article
• Online Publication Date: Aug 19, 2014
• Publication Date: Aug 28, 2014
• Deposit Date: Jun 12, 2023
• Journal: The Journal of Physical Chemistry C
• Print ISSN: 1932-7447
• Electronic ISSN: 1932-7455
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 118
• Issue: 34
• Pages: 19985-19994
• DOI: https://doi.org/10.1021/jp5041234
• Keywords: Surfaces, Coatings and Films; Physical and Theoretical Chemistry; General Energy; Electronic, Optical and Magnetic Materials