Resumo de eventos cient??ficos
Optical and magnetic nanocomposites containing Fe3O4@SiO2 grafted with Eu3+ and Tb3+ complexes
Autor
KHAN, L.U.
MURACA, D.
BRITO, H.F.
MOSCOSO-LONDONO, O.
FELINTO, M.C.F.C.
PIROTA, K.R.
TEOTONIO, E.E.S.
MALTA, O.L.
INTERNATIONAL CONFERENCE ON EXCITED STATES OF TRANSITION ELEMENTS, 6th
Resumen
The fabrication of bifunctional nanocomposites, co-assembling photonic (RE3+) and magnetic
(Fe3O4) features into single entity nanostructures is reported through a facile method, using Fe3O4
as core nanoparticles, which were coated with SiO2 shell and further grafted with Eu3+ and Tb3+
complexes. The sophisticated structural features and morphologies of the core-shell
Fe3O4@SiO2-(TTA-RE-L) nanomaterials were studied by Small-angle X-ray Scattering.
The core mean size , shell thickness , cluster
size ?? and fractal dimension DF were determined by
fitting the experimental SAXS data, corroborating
through Transmission Electron Microscopy images. The
DC magnetic properties at temperatures of 2 and 300 K
were explored in support to the structural conclusions
from SAXS and TEM analyses. The magnetic
contributions of the RE3+ ions to the magnetizations of
the Eu3+ and Tb3+ nanocomposites were discussed. The
photoluminescence properties of the Eu3+ and Tb3+
nanocomposites based on the emission spectral data and
luminescence decay curves were studied (Fig.1). The
experimental intensity parameters (??????), lifetimes (???),
emission quantum efficiencies (???) as well as radiative
(Arad) and non-radiative (Anrad) decay rates were
calculated and discussed, in addition, the structural
conclusions from the values of the 4f-4f intensity parameters
in the case of the Eu3+ ion. These novel Eu3+ and Tb3+ nanocomposites may act as red and
green emitting layers for magnetic and light converting molecular devices.