INVESTIGADORES
GIOVANETTI Lisandro Jose
congresos y reuniones científicas
Título:
Au@FexOy core@shell nanoparticles investigated by SAXS and XAFS techniques
Autor/es:
L.J. GIOVANETTI; F.G. REQUEJO; E.V. SHEVCHENKO; D.V. TALAPIN; M. SALMERON; A.F. CRAIEVICH
Lugar:
BI Convention Center - Campinas, Brazil
Reunión:
Congreso; 6th International Conference on Synchrotron Radiation in Materials Science; 2008
Institución organizadora:
LNLS
Resumen:
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Core/shell nanoparticles are
heteronanostructures that comprise a core of one material and a coating shell
of another material. The composition of the core and shell can be varied to
give a wide range of different properties. Since the size and material properties
of both the core and the shell can be manipulated at will, a vast range of
particles can be made with myriad properties, useful in areas like,
nano-sensors for cellular imaging, gap controlled semiconductor, etc.
The samples were synthesized in a two-step
procedure. Nanoparticles used as seed (core) are then incubated with a second
emulsion containing the monomers and initiators that will synthesize the shell.
In our case the nanoparticles under study have Au core and the shell is made of
iron oxide (FexOy).
To investigate the shape and size of the
nanoparticles we perform Transmission electron microscopy (TEM) and Small angle
X-ray scattering (SAXS) experiments on the core-shell system and seed
nanoparticles. Modeling the SAXS curves we determine an average core radius and
the thick of the shell. XAFS techniques
were used to determine the average oxidation state of Fe atoms in the shell in
addition we presents a combined study of
Au-L2,3 and Fe- K edges to investigate the charge transfer between the core (gold)
and the oxide shell (FexOy).
