Correlation of morphology and properties in magnetoelectric composites
T. Chistyakovaa, V. Vassilieva, E. Vladimirovaa, A. Nosovb
Institute of Solid-State Chemistry, Ural Department, Russian Academy of Sciences, Ekaterinburg,
Russia, Geoma2006@yandex.ru
b
Institute of Metal Physics, Ural Department, Russian Academy of Sciences, Ekaterinburg, Russia
a
Magnetoelecric composites of piezoelectric and piezomagnetic (ferrites) phases have stimulated their
research in the last few years due to significant technological potential in the novel multifunctional
devices. Magnetoelectric properties in a complicated way depend on the grain size, shape, density,
synthesis conditions and other factors. We investigated the BaTi0,8Zr0,2O3–CoFe2O4 system. Cobalt
ferrite powder was prepared by different techniques: standard ceramic method, thermal decomposition
of citrate precursor and thermal hydrolysis method (see SEM images in Figure). Comparative analysis
of correlation between the magnetoelectric properties, chemical composition, morphology, and
excitation frequency was carried out.
a
b
c
Figure. SEM image of the CoFe2O4 powder prepared by different techniques:
(a) standard ceramic method, (b) thermal decomposition of citrate precursor,
(c) thermal hydrolysis method
DFT study of interaction of nitric oxide with neutral and charged Ag8 clusters
V. E. Matulis, D. M. Palagin, A. S. Mazheika, O. A. Ivashkevich
Research Institute for Physical Chemical Problems, Belarusian State University,Minsk, Belarus,
e-mail: vitaly_matylis@mail.ru
Density functional theory has been used to study process of NO adsorption on neutral, anionic
and cationic Ag8 clusters. Two cluster types were investigated: structure I is the most stable
cluster in gas phase and structure II has the geometry of the most stable cluster adsorbed on rutile
TiO2 (110) surface [1]. Nine initial Ag8–NO structures were suggested based on orbital shape
analysis. Adsorption energies, N–O bond lengths and vibrational frequencies have been
calculated for all structures. It has been shown that in case of NO interaction with structure I the
corresponding adsorption energies grow in the following row: Eads(cation) < Eads(neutral) <
Eads(anion). However for structure II other dependence is found: Eads(anion) < Eads(cation) <
Eads(neutral).
References
1.
A. S. Mazheika, Vitaly E. Matulis, O. A. Ivashkevich, J. Mol. Struct. (Theochem) 47 (2010) 942.
Active sites on nanogold catalyst’s surface
in allylic isomerization: ab initio study
D. Mukhamedzyanova, D. Pichugina, A. Shestakov, N. Kuz’menko
M. V. Lomonosov Moscow State University, Moscow, Russia, lorineya@mail.ru
Gold nanoparticles are effective catalysts in allylbenzene
isomerization to cis- and trans-1-phenylpropene, and in case of
bimetallic AuNi particles the activity significantly increases.
For understanding of catalyst’s active sites quantum-chemical
simulation of allylic isomerization (but-1-ene, allylbenzene) in
the presence of model Aunz clusters (n = 1, 4, 19–21; z =–1, 0,
+1) have been carried out. It has been found that the efficiency
of catalyst in the reactions of double bond migration depends on
the charge and the structure of gold clusters; the corner
positively charged gold atoms on the surface play the important
role. The phenomenon of trans-product selective formation has
been explained.
The model of catalyst (Au21+ )
Thermal behaviour of the systems ZnO – MgO – NH4PO3
and ZnO – CaO – NH4PO3
G. L. Krul, A. I. Lesnikovich, A. F. Selevich
Research Institute for Physical Chemical Problems, Belarusian State University, Minsk, Belarus,
e-mail: selevich@bsu.by
It was found earlier that large majority of the double systems MIIO–NH4PO3 (MII = Mg, Ca, Mn,
Co, Ni, Cu, Zn, Cd, and Pb) demonstrated similar schemes of crystalline phase transformations.
In particular, an increase in temperature from 300 to 400 °C and in reaction time causes the
consecutive crystallization of the following compounds: M(NH4)2(PO)4 or M(NH4)2P4O12,
MNH4(PO3)3 or MNH4P3O9, M(PO3)2 or M2P4O12 [1]. It was shown also that double ammoniumcontaining condensed phosphates are the promising flame retardant additives to polyamides [2].
The aim of this work was to study an opportunity to obtain ternary ammonium-containing
condensed phosphates in the systems ZnO–MgO–NH4PO3 and ZnO–CaO–NH4PO3. Reactions of
metal oxides initial mixtures (molar ratio ZnO : Mg(Ca)O = 1 : 3 and 3 : 1) with NH4PO3 at the
molar ratio MO : NH4PO3 = 1 : 6 were investigated at the temperatures 300 and 400 ºC. As a
result, conditions for obtaining ammonium-containing condensed phosphates based on structural
types of CaNH4P3O9, ZnNH4(PO3)3, MgNH4(PO3)3 and MgNH4P3O9 have been determined.
References
1. A. F. Selevich, E. V. Grushevich, L. S. Ivashkevich, G. L. Krul, N. V. Ilushchenko, A. I.
Lesnikovich. Phosphorus Res. Bull. 19 (2005) 228/
2. G. F. Levchik, S. V. Levchik, A. F. Selevich, A. I. Lesnikovich, A. V. Lutsko, L. Costa. Fire
Retardancy of Polymers. The Use of Intumescence. 1998. P. 280/
Photochromic systems based on bifunctional derivatives of cyclopentadienyl
manganese(II) tricarbonyl
a
E. Kelbyshevaa, M. Ezernitskayaa, T. Strelkovaa, Y. Borisova, L. Teleginaа, N. Loima.
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences,
Moscow, Russia, e-mail: loim@ineos.ac.ru
With the aim of designing photochromic compounds photochemical reactions of
monosubstituted cymantrenes with two functional groups such as allyl, carbamate or amide and
pyridine residue (Fig.) have been studied by means of IR, UV-vis, and NMR spectroscopies. In
all cases (excluding 5) two spectroscopically different dicarbonyl chelates are formed due to UV
irradiation at 366 nm. For example, photolysis of 2 leads to formation of an alkene chelate and a
complex with Mn-O=CMe bond; each of them reverts to tricarbonyl compound 2 in the dark
reaction. However, in the case 1 the photochromic pair occurs due to linkage isomerisation of
olefine and carbamate chelates.
CH3
CH
Mn(CO)3
N
OCOC
CH3
CH3
CH3
Mn(CO)3
1
N
COCH3
C
N
OCOC
4
CH3
CH3
CH3
CH
CH3
CH
Mn(CO)3
O
CH2
N
O
Mn(CO)3
2
CH3CH3
Mn(CO)3
CH
3
N
5
Figure. Structural formulas of monosubstituted cymantrenes under investigation
References
1. L. N. Telegina, M. G. Ezernitskaya at all. Eur. J. Inorg. Chem., 24 (2009) 3636.
Microcapsules on the basis of pectin and protamine sulfate
K. Hilevskaya, E. Gracheva, T. Shutava, V. Agabekov
Institute of Chemistry of New Materials of NAS of Belarus, Minsk, Belarus,
e-mail: k_hilevskay@mail.ru
Microcapsules on the basis of pectin and protamine sulfate were fabricated by the layer-by-layer
(LbL) self-assembly technique. The hollow multilayer (PtS/Pect)n shells were obtained by
dissolution of template carbonate cores in a HCl solution. The microcapsules were stored as an
aqueous suspension at 4 °C and proven to be stable as long as 3 months. According to AFM
analysis, the diameter of hollow microcapsules is equal to 3÷5 μm; the value is comparable with
the diameter of initial matrix (Figure). The average thickness of the four bilayer microcapsule
walls do not exceed 20 nm. The obtained (PtS/Pect)4 microcapsules are promising for biomedical
applications.
Figure 1. The hollow (PtS/Pect)4 microcapsules: a) AFM image; b) TEM image.