4th EucheMs chemistry congress

Poster Session 2
s1240
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - Nanochemistry, Nanotechnology
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A SAMPLe CheMiCAL route towArd
MonodiSPerSe iron CArBide nAnoPArtiCLeS
diSPLAyinG tunABLe MAGnetiC And
unPreCedented hyPertherMiA ProPertieS
A. Meffre 1 , B. MehdAoui 1 , v. KeLSen 1 ,
P. f. fAzzini 1 , J. CArrey 1 , S. LAChAize 1 ,
M. reSPAud 1 , B. ChAudret 1
1 INSA, GP, Toulouse, France
Monodisperse and air stable magnetic nanoparticles
displaying high magnetization and tunable anisotropy are highly
desirable for several nanotechnology applications1 . However,
among the various magnetic nanoparticles previously described,
no one fills of these properties. A recent study in our group reveals
that iron(0) nanoparticles could be good candidates for
hyperthermia but lack the air-stability criteria2 . In contrast,
iron/iron oxide core-shell and iron oxide nanoparticles display a
good air-stability but a low magnetization. An improvement of
these behaviors requires either coating iron(0) nanoparticles with
a protective shell or changing the chemical nature of the particles3 .
In this respect, iron carbides nanoparticles are particularly
attractive since combining high magnetization, air stability and
the possibility to modulate the magnetic properties as function of
carbon content. But up to now no wet chemical methods for their
synthesis were described.
Here, we report the first chemical synthesis sample and
reproducible for the preparation of monodisperse iron carbides
and iron/iron carbides nanocrystals with controlled sizes and
compositions4 . The synthesis deriving from the Fischer Tropsch
mechanism is original and is based on decomposition of Fe(CO) 5
on different mild conditions on a colloidal solution of iron(0) NPs
stabilized by hexadecylammonium chloride and hexadecylamine5 .
Under dihydrogen atmosphere, we were able to enlarge the
particle size and activate the carbon diffusion inside the iron
nanoparticle. Their mean size is well controlled by adjusting the
seeds one and/or the Fe(CO) concentration. All these
5
nanoparticles display excellent magnetic properties and airstability.
More, by tunning the experimental conditions, as
temperature and reducing agent, we can control the amount of
carbon diffused inside and therefore their magnetic anisotropy.
However, these nanoobjects have no precedent and some of
them display the highest efficiency so far reported for magnetic
hyperthermia in the current operating treatment conditions.
Keywords: nanoparticles; magnetic properties;
4 th EucheMs chemistry congress
P - 0 7 5 6
PrePArAtion of PerovSKite oxide thin fiLM
eLeCtrodeS By rf MAGnetron SPutterinG
for environMentAL APPLiCAtionS
M. e. MeLo JorGe 1 , M. i. SivA PereirA 1 , A. roviSCo 2 ,
J. S. MArtinS 2 , y. nuneS 2 , S. Sério 2
1 CCMM, Departamento de Química e Bioquímica Faculdade
de Ciencias da Universidade de Lisboa, Lisboa, Portugal
2 CEFITEC, Departamento de Física Faculdade de Ciencias e
Tecnologia da Universidade Nova de Lisboa, Lisboa, Portugal
The search of new and more efficient methods for the
treatment of effluents containing several persistent pollutants
species is a very important issue. Electrochemical technology
offers an efficient and environmental friendly approach for the
elimination of different kinds of pollutants. The removal of
metallic ions from solution by electrochemical reduction is a well
known process. Depending on the cathode material and applied
potential, a selective recovery of metals from solution can be
performed.
Perovskite type structure oxides are potential materials for
this application. However, special attention must be given to the
electrode construction, in particular its mechanical stability. The
sputtering technique presents several advantages on electrodes
preparation [1] such as high deposition rates, high-purity films and
extremely high adhesion film/support.
The main objective of this work was to optimize the growth
conditions for obtaining crystalline Ca Sm MnO thin films
1-x x 3
prepared by an innovative approach using the magnetron
sputtering technique. The films were prepared by radio frequency
magnetron sputtering under various deposition conditions using
nanosized powder compacted targets. The polycrystalline samples
Ca Sm MnO used as targets were previously prepared by
1-x x 3
self-combustion method using citric acid [2] . The plasma medium
was characterized using optical emission spectroscopy.
The characterization of the bulk and the thin films were
performed using different tools. The structural and morphological
characterization was carried out by X-ray diffraction (XRD),
scanning electron microscopy (SEM) and atomic force
microscopy (AFM).
Acknowledgements: Financial support from FEDER,
through Programa Operacional Factores de Competitividade–
COMPETE, and Fundacio para a Ciencia e a Tecnologia–FCT,
for the projects PTDC/AAC-AMB/103112/2008.
references:
1. S. Sério, M. E. Melo Jorge, M. J. P. Maneira, Y. Nunes,
Mat. Chem. Phys., 126 (2011) 73-81.
2. I. Matos, S. Sério, M. E. Lopes, M. R. Nunes,
M. E. Melo Jorge, J.Alloys Compds, 509 (2011) 9617–9626.
Keywords: Perovskite phases; Thin films; Nanotechnology;
Surface analysis; X-ray diffraction;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc