Resumo de eventos cient??ficos
Mn-Zn ferrite nanoparticles probed by synchrotron pair distribution function analysis and anomalous X-ray scattering
Autor
ICHIKAWA, R.U.
PARRA, J.P.R.L.L.
VALLCORBA, O.
PERAL, I.
YOSHITO, W.K.
SAEKI, M.J.
TURRILLAS, X.
MARTINEZ, L.G.
RAU ANNUAL USERS MEETING LNLS/CNPEM, 27th
Resumen
Among the numerous applications of Mn1-xZnxFe2O4 nanoparticles we can highlight
biomedical applications as magnetic tracer in Alternate Current Biosusceptometry
(ACB), Magnetic Resonance Imaging (MRI), for diagnosis of cancer and others diseases
as diabetes and Parkinson, whose severity can be monitored by analyzing the disturbances
of the gastrointestinal motility [1,2]. Specifically, the former (ACB) method is promising
because of its low cost, it is non-invasive method and because it can be conducted without
ionizing radiation. Major advances have been achieved by developing a bionanocomposite
based on ferrites for the theranostics [3] as well, of breast cancer, by
carrying drugs or hyperthermia. Recently, we reported that Mn0.75Zn0.25Fe2.8O4
nanoparticles with different surface charge can be produced precipitating them by NaOH
with different concentrations [2]. This behavior is observed if an excess of Iron is
introduced to the ferrite. Five samples precipitated with different NaOH concentrations
were analyzed by X-ray synchrotron diffraction (XRD) which revealed a less crystalline
phase contribution alongside the main peaks of the cubic spinel ferrite phase. Pair
Distribution Function (PDF) analysis was used to probe the local structure and showed
that Fe-Fe, Mn-Mn and Zn-Zn bond distances in the 3.0 up to 3.5 ?? range are different
from the ones usually reported in the literature. Lastly, for the sample with best magnetic
behavior anomalous X-ray scattering (AXS) using three energies close to the absorption
edges of Mn, Zn and Fe was applied to determine its cation distribution complementing
the previous result from PDF analysis. Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico (CNPq) CNPq: 206983/2014-0