ZnxFe3-xO4 nanoparticles: effects of morphology, magnetism and composition on the Magnetic Fluid Hyperthermia response

A. ASENJO; E. LIMA JR., A. D. ARELARO, L. M. ROSSI, P. KYOHARA, R. D. ZYSLER AND H. R. RECHENBERG; E.L. WINKLER; E. DEL BARCO, M. DURAN, J.M. HERNÁNDEZ, J. TEJADA, R.D. ZYSLER, M. VASQUEZ MANSILLA, D. FIORANI; H.E. TROIANI; C. RAMOS, E. DE BIASI, R.D. ZYSLER; R.D. ZYSLER; D. VALDÉS; L. RODRÍGUEZ; D. FREGENAL; G.F. GOYA; T. TORRES MOLINA

S.C. de Bariloche

Simposio; XXIII Latin American Symposium on Solid State Physics (XXIII SLAFES); 2018

SLAFES

Magnetic Fluid hyperthermia (MFH) consists in the heating of a target tissue by the magnetic losses of a ferro- or ferrimagnetic materials (MNPs) using ac magnetic eld with frequency between 100kHz and 1MHz. Ferrite nanoparticles are interesting systems for MFH whit a large number of potential applications in this eld. The key parameter in MFH is the specic power absorption (SPA) of the nanoparticles, and is determined by the magnetic, morphological and rheological properties of the solvent/MNPs. In this work, we present a study of the morphological and magnetic properties of ZnxFe3􀀀xO4 nanoparticles in order to understand their MFH response. By controlling the size and the composition of our samples we tune the eective magnetic anisotropy and the saturation magnetization, which allow us to optimize the SPA of our material in MFH experiments. MNPs of dierent sizes between 8-30nm where synthesized by high temperature thermal decomposition of organometallic precursors. The morphology of the nanoparticles was determined by TEM, the composition was analyzed by PIXE, and the magnetic properties were determined by magnetization measurements and ferromagnetic resonance experiments. The magnetic hyperthermia experiments were performed as a function of both frequency, between 228 kHz and 817 kHz, and amplitude, up to 300 Oe, in dierent rheological conditions (i. e., dierent viscosities). The resulting SPA values were analyzed in terms of the dierent mechanisms that determine the magnetic losses. These mechanisms are related to the magnetic relaxation of the nanoparticles moment and its phase shift respect to the ac applied eld. With a simple model, we were able to analyse the dependence of the SPA with the frequency for the dierent samples. We also present measurements of the catalytic peroxidase-like activity to produce free radicals of the nanoparticles under emulated physiological conditions, which is critical for potential clinical uses of these systems.