TY - JOUR

T1 - High frequency hysteresis losses on $-Fe2O3 and Fe3O4: Susceptibility as a magnetic stamp for chain formation

T2 - Susceptibility as a magnetic stamp for chain formation

AU - Morales, Irene

AU - Costo, Rocio

AU - Mille, Nicolas

AU - Da Silva, Gustavo B

AU - Carrey, Julian

AU - Hernando, Antonio

AU - De la Presa, Patricia

N1 - Publisher Copyright: © 2018 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2018

Y1 - 2018

N2 - In order to understand the properties involved in the heating performance of magnetic nanoparticles during hyperthermia treatments, a systematic study of different γ-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 χ 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.

AB - In order to understand the properties involved in the heating performance of magnetic nanoparticles during hyperthermia treatments, a systematic study of different γ-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 χ 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.

KW - Hyperthermia

KW - Iron oxide

KW - Magnetic nanoparticles

KW - Specific absorption rate

UR - http://www.scopus.com/inward/record.url?scp=85057307827&partnerID=8YFLogxK

U2 - 10.3390/nano8120970

DO - 10.3390/nano8120970

M3 - Article

VL - 8

SP - 970

JO - Nanomaterials

JF - Nanomaterials

SN - 2079-4991

IS - 12

M1 - 970

ER -