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Author1 Names1, Author2 Names (First, Last)2,*), separated by commas in Times
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1
Faculty of Technical Physics and Nanotechnology, VNU-University of Engineering and Technology
144 Xuan Thuy, Cau Giay, Ha Noi, Viet Nam
2
Faculty of Physics, VNU-Hanoi University of Science
334 Nguyen Trai, Thanh Xuan, Ha Noi, Viet nam
Corresponding author's email: fms2013@fmsconference.org
The nanofluids containing the surface activated particles have great application potential in modern
technology. In this paper, we studied the optical properties of the ceramic particles of forms Ca(FeMn)O3
and (CaPr)(MnRu)O3 dispersed in water solution by using SPAN-80 as surface activated agent (called
surfactant). ... (maximum 300 words)
Keywords (3 at least): Perovskite; Manganate; Structure; Electronic.
1. Introduction
As modern spintronic materials with many interesting properties, the perovskite manganates
deserve a special attention of scientists worldwide. There are a variety of changes taken in the
electronic, magnetic, thermal and mechanical properties of these materials when elements in A
and B positions of the perovskite stoichiometric formula ABO3 are substituted by the third
elements, either metals, transition metals or non-metals...
2. Experiments
At first, the Ca(FeMn)O3 and Ru-doped (CaPr)MnO3 ceramic samples were fabricated by
classical solid reaction method from highly purified precursors (purity greater than 99,9%). We
grinded 0,6 g Ca(FeMn)O3 and Ru-doped (CaPr)MnO3 in pure water, then 30 ml water was added
to create the 2% solutions (weight basis)...
3. Results and discussion
Figure 1 and 2 show that the IR absorption spectra of Fe and Ru doped samples. (Now, we
named that the samples doped with Fe is L1 and with Ru is L2). Fig. 1 reveals that the absorption
of L1 is not strong in a visible region, but L2 shows the enhencement of absorption in the
wavelength range from 450 to 600 nm. The absorption in UV region was not clearly observed yet.
The photoemission spectra of solid-samples have never been observed, basically because of
strong interparticle absorption. The photoemission of perovskite manganates is very interesting
phenomenon and we think it may be related to the surface effect of nanoparticles being activated
by colloidal agent (SPAN-80). Detailed analysis will need more time to perform with more
advanced techniques, including the theoretical evaluation by quantum chemical methods. We
leave this for consideration in the future.
Fig 1. The IR absorption spectra of Ca(FeMn)O3
Table 1. Electrical properties of colloidal substances
Compounds
CaMnO3
CaRuMnO3
Dielectric
constants
Resistance
[k]
1.348 x 10
5
14.23
1.561 x 10
4
2.93
4. Conclusion
We have presented an initial research on the optical properties of the ceramic compounds
Ca(FeMn)O3 and Ru-doped (CaPr)MnO3 in their colloidal form. The results showed that the
dispersion of ceramic particles by colloidal agents (SPAN-80) led to the significant increase of
absorption and emission ability of these samples (whose bulk states showed weak or did not show
such effect). The effects presented are believed to be observed for the first time in our laboratory.
References
1. R. Gundakaram, P. V. Arulraj Avanitha, C. N. R. Rao, N. Gayathri, A. K. Raychaudhuri, A. K.
Cheetham, “Effect of Cr substitution on the crystal and magnetic structure of (Pr 0.55Ca0.45)MnO3: A
neutron powder diffraction investigation", J. Solid State Chem. 127 (1996) 354.
2. K. Yoshii, A. Nakamura, “Reversal of Magnetization in La0.5Pr0.5CrO3”, J. Solid State Chem. 155
(2000) 447.
3. X.J. Liu, Z.Q. Li, P. Wu, H.L. Bai, E.Y. Jiang, “The effect of Fe doping on structural, magnetic and
electrical transport properties of CaMn1−xFexO3 (x = 0–0.35)”, Solid State Communications 142 (2007)
525–530.