RT Journal Article
T1 High frequency hysteresis losses on gamma-Fe_2O_3 and Fe_3O_4: susceptibility as a magnetic stamp for chain formation
A1 Morales Casero, Irene
A1 Hernando Grande, Antonio
A1 Presa Muñoz del Toro, Patricia de la
A1 Costo Cámara, Rocío
A1 Mille, Nicolas
A1 Bezerra Da Silva, Gustavo
A1 Carrey, Julian
AB In order to understand the properties involved in the heating performance of magnetic nanoparticles during hyperthermia treatments, a systematic study of different gamma-Fe_2O_3 and Fe_3O_4 nanoparticles has been done. High-frequency hysteresis loops at 50 kHz carried out on particles with sizes ranging from 6 to 350 nm show susceptibility chi increases from 9 to 40 for large particles and it is almost field independent for the smaller ones. This suggests that the applied field induces chain ordering in large particles but not in the smaller ones due to the competition between thermal and dipolar energy. The specific absorption rate (SAR) calculated from hysteresis losses at 60 mT and 50 kHz ranges from 30 to 360 W/g_Fe, depending on particle size, and the highest values correspond to particles ordered in chains. This enhanced heating efficiency is not a consequence of the intrinsic properties like saturation magnetization or anisotropy field but to the spatial arrangement of the particles.
PB MDPI
SN 2079-4991
YR 2018
FD 2018-12
LK https://hdl.handle.net/20.500.14352/13074
UL https://hdl.handle.net/20.500.14352/13074
LA eng
NO ©2018 by the authors.This research was funded by COST action RADIOMAG (TD1402), supported by COST (European Cooperation in Science and Technology), by the Spanish Ministry of Economy and Competitiveness (MAT2015-67557-C2-1-P), and by Nanomag European project (604448) seventh framework program.
NO Unión Europea. FP7
NO Ministerio de Economía y Competitividad (MINECO)
DS Docta Complutense
RD 4 may 2024