Resumo de eventos cient??ficos
Synthesis and characterization of Fe3O4-HfO2 nanoparticles by magnetization and hyperfine interactions measurements
Registro en:
0000-0002-4499-5949
0000-0003-3023-1718
Autor
MATOS, IZABELA T.
SALES, TATIANE S.
CABRERA-PASCA, GABRIEL
BURIMOVA, ANASTASIA
SAXENA, RAJENDRA N.
PEREIRA, LUCIANO F.
OTUBO, LARISSA
CARBONARI, ARTUR W.
ANNUAL CONFERENCE ON MAGNETISM AND MAGNETIC MATERIALS, 65th
Resumen
Nanoparticles (NPs) that combine biocompatibility and enhanced physical characteristics for
biomedical applications are currently an area of intense scientific research. Hafnium oxide NPs is an innovative
approach in the anticancer treatment by radiotherapy due to their low toxicity and enhancement of local dose
in the tumor reducing the total radiation dose for the patient [1]. The combination of this amazing property with
the excellent magnetic hyperthermia performance of Fe3O4 NPs can produce a promising nanomaterial for
cancer therapy. In the present work, we have synthesized NPs samples of Fe3O4 doped with 10%Hf and HfO2
doped with 10% Fe by chemical procedures. The samples had their morphological, structural, and magnetic
properties characterized by some results being displayed in Fig. 1. The crystal structure of the samples was
characterized by X-ray Diffraction (XRD), whose results present a single phase. Transmission Electron
Microscopy (TEM) images show spherical and hexagonal NPs with an average size of 12 nm as displayed in
Fig. 2. The magnetic property was investigated by magnetization measurement. The results from the
temperature dependence of ZFC-FC magnetization show a large peak in the ZFC curve corresponding to a
broad distribution of blocking temperatures as shown in Fig. 1(b). Fortunately, when irradiated with neutrons in
a research reactor, the nuclear reaction 180Hf(n,??)181Hf yields the probe nucleus 181Hf(181Ta) used by the
perturbed angular correlations (PAC) technique to measure hyperfine interactions. Both samples show electric
quadrupole interaction characteristics of the HfO2 phase indicating that the Fe replaces Hf in HfO2 NPs, but
rather than substituting Fe, Hf form HfO2 NPs diluted in Fe3O4 NPs. Moreover, a pure time-dependent
magnetic dipole interaction below 300 K was observed for Fe3O4 NPs mixed with 10% of HfO2.