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7/30/2019 p149.pdf
1/1
Proceedings of the 4th International Conference on
Nanostructures (ICNS4)12-14 March 2012, Kish Island, I.R. Iran
Abstract Book|INST| Sharif University of Technology| 149
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MAG 007
MAG 009
MAG 006
Y-Pt- Fe3O4 nanoparticles were prepared by a simple method. Syn-thesis of nanoparticles of Fe3O4 was rst performed. Then Pt- Fe3O4nanoparticles were prepared with adding K2PtCl6 in Fe3O4 nanopar-
ticles solvent via reduction of K2PtCl6 in Fe3O4 nanoparticles by
NaBH4. For studying the effect of rare earth oxides on Pt- Fe3O4nanoparticles, Y2O3 was added to the Pt- Fe3O4 solvent. The synthe-
sized nanoparticles were characterized by X-ray diffraction (XRD)
and scanning electron microscopy (SEM). These nanoparticles have
chemically disordered structures. Susceptibility of prepared nanopar-
ticles was measured by Susceptometer. The hysteresis loop of Y-Pt-
Fe3O4 nanoparticles was taken by vibrating sample magnetometer
(VSM). The asmade nanoparticles have coercivity below 100 Oe and
are superparamagnetic in room temperature.
Keywords: Y-Pt-Fe3o4 nanoparticles; Magnetic properties; Superpara-
magnetic; Coersivity; Susceptibility
Z. Golsanamloua*, M. M Golzana, A. Hassanzadehba Department of Physics, University of Urmia, 165, Iranb
Department of Chemistry, University of Urmia, 165, Iran*[email protected]
Synthesis of Superparamagnec Nanoparcles with
Adding Yrium Oxide on Pt-Fe3O4 Nanoparcles
Nanocrytalline samples of La0.7Sr0.3MnO3 were synthesized by me-chanical activation method in ambient conditions and post sintering
at 900 C. The structural, magnetotransport, and magnetovolume
properties of the samples were investigated. The results show a metal-
insulator transition at TMI = 165 K, a ferro-paramagnetic transition at
TC = 160 K and a colossal magnetoresistance (CMR) value of about
40% under the eld of 1.5 T around TMI, which are markedly affected
by the small grain size (9 nm) of the studied samples. This is attributed
to the enhanced intergrain resistivity and spin-polarized tunnelling be-
tween neighbouring grains in the present granular samples. Besides,
the anomalous behaviour of magnetoresistance, thermal expansion
and its coefcient observed around TC of the samples can be explained
on the basis of a magnetic two-phase state.
Keywords: Manganites; Magnetoresistance; Thermal expansion; Me-
chanical activation
Sh. Tabatabai Yazdi*, Sh. Abareshi, N. Tajabor, M. Rezaee Roknabadi, M.BehdaniDepartment of Physics, Faculty of Sciences, Ferdowsi University, Mashhad91775-1436, Iran*[email protected]
Magnetotransport and Magnetovolume Eects in
La0.7Sr0.3MnO3 Nanocrystalline Perovskites Prepared by
Mechanical Acvaon Method
In this work, magnetic nanoparticles were generated by pulsed laser ir-
radiation on the Nd-Fe-B-C magnetic target in Distilled water. Charac-
terization of nanoparticles in terms of size, shape, chemical composition
and magnetic properties was carried out by transmission electron mi-
croscopy (TEM), energy dispersive X-ray (EDAX), Fourier transform
infrared spectroscopy (FTIR), magnetic force microscope (MFM). The
exposure times were performed on 1, 5 and 10 min. increasing of the
exposure time leads to reduce the mean diameter of the nanoparticles,
with minimum size of around 3 nm, growth of the nanoparticle number
and decreasing of the nanoparticle creation rate. The chemical compo-
sition of nanoparticles was similar to the bulk sample. MFM shows thatthe nanoparticles have the magnetic properties.
Keywords:Magnetic nanoparticles; Nd:YAG Laser; Nd-Fe-B-C magnet
S. Seifollahi, H. Dehghanpour*Department of physics, Tafresh University, Tafresh, 39518-79611, Iran*[email protected]
Physical Properes of Magnec Nd-Fe-B-C Nanoparcles
Generated in Dislled Water Using Nd:YAG Laser
MAG 008
The inuence of Co concentration (x) on the structural, magneto-opti-
cal properties of CoxTi1-xO2 lms has been investigated. The lms were
deposited by spray pyrolysis technique on Si(100) substrates at 475C
using a hydro-alcoholic solution containing of titanium (iv) isopropox-
ide and Co(NO3)2 with various Co-doping levels of x=0, 0.003, 0.008,
and 0.015. The effect of annealing atmosphere on structural and elec-
tronic structure of the lms was investigated. X-ray diffraction analysis
shows that the lms have pure phase of TiO2. Atomic force microscope
(AFM) study shows that the annealing does not change signicantly
the grain size and microstructure of the samples. Room temperature
magneto-optical characterization in polar mode shows hysteresis loops
for the samples annealed in H2 gas as well as a paramagnetic behav-
iour for the samples which were annealed in air. X-ray photoelectron
spectroscopy (XPS) analysis shows the presence of Co2+ high spin forsample with x=0.008 which annealed in H2. It shows that Co atoms are
bounded to oxygen and there is no metallic bound in anatase structure.
Therefore, the origin of magnetization could be attributed to the role of
oxygen vacancies in anatase thin lms.
Keywords: Diluted magnetic semiconductors; Grazing incident angle
of X-Ray diffraction; Magneto-optical Kerr effect
M. Karimipoura, b, c*, M. Magetod, e, N. Shahtahmasebia, b, M. Rezaee Roknaba-da, b, R. Etefagha, b, E. Azhira, b, M. Mwamburie, Z. Topaliand, P. Svedlindhda Nano Research Centre, Faculty of Basic Science, Ferdowsi University ofMashhad, Mashhad, Iranb Department of Physics, Faculty of Basic Science, Ferdowsi University ofMashhad, Mashhad, Iranc Department of Physics and Astronomy, Uppsala University, Uppsala 516,SE-75120, Sweden
Room Temperature Magnezaon of Co-doped TiO2
Thin Films Prepared by Spray Pyrolysis Technique
dDepartment of Engineering Sciences, ngstrom Laboratory, Uppsala Uni-versity, Uppsala 534, SE-751 21, Swedene Department of Physics, Moi University, Eldoret 1125, Kenya*[email protected]