ISSN 1070-4272, Russian Journal of Applied Chemistry, 2017, Vol. 90, No. 3, pp. 342−348. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © A.Sh. Khaliullina, V.M. Kuimov, S.A. Belyakov, L.A. Dunyushkina,
2017, published in Zhurnal Prikladnoi Khimii, 2017, Vol. 90, No. 3,
PROCESSES USING VARIOUS
Chemical Synthesis and Granulometric Composition
A. Sh. Khaliullina*, V. M. Kuimov, S. A. Belyakov, and L. A. Dunyushkina
Institute of High-Temperature Electrochemistry, Ural Branch, Russian Academy of Sciences,
ul. Akademicheskaya 20, Yekaterinburg, 620137 Russia
* e-mail: Adelia01@mail.ru
Received January 24, 2017
powders were synthesized by chemical solution methods: modiﬁ ed Pechini method and from
solutions of inorganic salts in water and ethanol. The structure crystallizes into the orthorhombic type upon annealing at
1000°C for powders prepared by the Pechini method and from solution of salts in water. It was shown that CaZr
powders synthesized by various methods have different dispersities. The results obtained in a study of the granulometric
composition by the sedimentation method and microscopic analysis enable fabrication of dense and mechanically strong
electrolyte ﬁ lms and ceramics.
Calcium zirconate doped with acceptor impurities
exhibits proton conductivity in humid or hydrogen-
containing media [1, 2]. It is known that materials based
on calcium zirconate have high chemical and thermal
stability [3, 4]. Owing to the combination of these
properties, materials based on calcium zirconate are
promising for various electrochemical applications: they
are used as electrolyte in hydrogen sensors, electrolyzers,
fuel cells, etc. [2, 5, 6].
Materials based on calcium zirconate are synthesized
by different methods. A widely used technique is that by
solid-phase synthesis in which a homogeneous mixture
of powdered reagents is prepared by thorough mixing,
with compaction and high-temperature calcination and,
occasionally, with intermediate grindings [2, 5, 7–9].
A disadvantage of this synthesis method is that it requires
a prolonged calcination at very high temperatures of
1600°C and more because of the large particle size of the
starting powders and slow solid-phase diffusion, which
restricts the formation rate of the complex solid oxide.
For example, the authors of  obtained single-phase
ceramic samples (x = 0.03–0.10) by an-
nealing in a vacuum furnace at a temperature of 1800°C.
One more disadvantage of the solid-phase synthesis, in
addition to the high synthesis temperatures, is the con-
tamination of the powder with the material of milling
bodies in the grinding stage. The powders synthesized by
the solid-phase method are coarsely dispersed and have
wide particle-size scatter.
Finely dispersed powders are produced by solution
synthesis methods. In solutions, substances are dispersed
on the atomic or molecular level, and, therefore, the
synthesis temperature is substantially lower than that in
the solid-phase method. As a rule, powders produced by
solution methods have large speciﬁ c surface area and, as a
consequence, exhibit high sintering and catalytic activities.
Finely dispersed powders are used to obtain solid-
oxide electrolyte ﬁ lms by the powder, electrophoretic, and
combined powder-solution methods [10–12]. These ﬁ lm-
producing methods use suspensions containing a nanosize
electrolyte powder. Finely dispersed powders are also
used to obtain ceramics with high density, mechanical
strength, and other prescribed properties [9, 13].
The number of publications devoted to solution
methods for synthesis of CaZrO
small, although these methods can yield ﬁ nely dispersed
powders at substantially lower annealing temperatures,
compared with the solid-phase technique. Benxue
Liu et al.  synthesized a nanodispersed calcium