Structural Properties and State of a Zirconium Dioxide Surface Layer Modified with Mе3+ Cations

Article abstract of DOI:10.1134/S0036024418090145

Abstract: The effect Ме³⁺ (Al, Y, Sc, Fe, and Mn) cations on the structural properties and state of a zirconium dioxide surface layer is investigated. The thermal stability of the Ме³⁺ solid solutions based on a metastable zirconium dioxide modification is established via X-ray diffraction analysis. It is shown using X?ray photoelectron spectroscopy that the distribution of surface–volume cationic modifier is determined by the type of cation. In Al-, Fe-, and Mn-ZrO₂ systems, modifiers are mainly distributed over a surface; in Y and Sc-ZrО₂, modifiers are distributed uniformly. The nature of the cation distribution affects the thermal stability of the solid solutions formed.

Full text of DOI:10.1134/S0036024418090145

ISSN 0036-0244, Russian Journal of Physical Chemistry A, 2018, Vol. 92, No. 9, pp. 1799–1805. © Pleiades Publishing, Ltd., 2018.
Original Russian Text © L.I. Kuznetsova, A.V. Obukhova, G.N. Bondarenko, O.Yu. Fetisova, Yu.L. Mikhlin, S.D. Kirik, P.N. Kuznetsov, 2018, published in Zhurnal Fizicheskoi Khimii,
2018, Vol. 92, No. 9, pp. 1470–1477.
PHYSICAL CHEMISTRY
OF SURFACE PHENOMENA
Structural Properties and State of a Zirconium Dioxide Surface Layer
Modified with Mе3+ Cations
L. I. Kuznetsovaa, A. V. Obukhovaa,*, G. N. Bondarenkoa, O. Yu. Fetisovaa, Yu. L. Mikhlina,
S. D. Kirikb, and P. N. Kuznetsova
aInstitute of Chemistry and Chemical Technology, Siberian Branch, Russian Academy of Sciences,
Federal Research Center “Krasnoyarsk Science Center SB RAS”, Krasnoyarsk, 660036 Russia
bSiberian Federal University, Krasnoyarsk, 660041 Russia
*е-mail: lab9team@rambler.ru
Received November 24, 2017
Abstract—The effect Ме3+ (Al, Y, Sc, Fe, and Mn) cations on the structural properties and state of a zirco-
nium dioxide surface layer is investigated. The thermal stability of the Ме3+ solid solutions based on a meta-
stable zirconium dioxide modification is established via X-ray diffraction analysis. It is shown using X-ray
photoelectron spectroscopy that the distribution of surface–volume cationic modifier is determined by the
type of cation. In Al-, Fe-, and Mn-ZrO2 systems, modifiers are mainly distributed over a surface; in Y and
Sc-ZrО2, modifiers are distributed uniformly. The nature of the cation distribution affects the thermal stabil-
ity of the solid solutions formed.
Keywords: stable and unstable zirconium dioxide modifications, сationic promotion, zirconium hydroxide,
stabilization, phase transformations
DOI: 10.1134/S0036024418090145
INTRODUCTION
that an important factor in stabilizing the nonequilib-
rium forms of ZrO2 is the formation of diffusion barri-
ers (kinetic retardation) during crystallization.
Metastable modifications of some oxides (zirco-
nium, aluminum, titanium, iron, etc.) belong to the
families of refractory and ceramic materials, ionic
conductors, and nanocomposites with unique cata-
lytic and sorption properties [1–9]. At the same time,
the mechanism behind the stabilization of individual
oxides and multicomponent systems based on them in
the thermodynamically unstable states has yet to be
established. Because of its unique set of physicochem-
ical properties, zirconium dioxide in its metastable
(tetragonal and cubic) modifications has been the
object of intense investigations, but the nature of the
factors responsible for the formation of nonequilib-
rium forms and their stability remains unclear [10, 11].
The formation of tetragonal ZrO2 nanocrystals can
also be observed in the absence of cationic additives
when hydrothermal and mechanochemical synthesis
and sol–gel technology are used [17–19]. When
speaking about the origin of stabilization, the most
important factor is the size effect, due to which tetrag-
onal modification becomes energetically more advan-
tageous than monoclinic modification with ZrO2
crystallite sizes smaller than 30 nm, due to the lower
free surface energy [20]. This viewpoint is supported
by the results from modifying ZrO2 surfaces in prepar-
ing acid catalysts by depositing sulfate, tungstate, and
borate anions onto amorphous zirconium oxyhydrox-
It is generally assumed that the crystallization of
zirconium dioxide in its metastable modifications ide [8, 9, 15, 21, 22]. Upon calcination, anion-con-
upon the addition of Me2+ and Me3+ cations is caused
taining ZrO2 surface layers form that slow the crystal-
by the formation of solid solutions that can alter the lization process and help to stabilize the nanocrystal-
thermodynamic characteristics of an oxide system [12, line tetragonal modification. A similar role can be
13]. The formation of solid solutions with heterovalent played by surface solid solutions of the different cat-
cations results in defects, specifically anionic vacan- ions in ZrO2. The surface oxide clusters of cationic
cies in the oxygen sites of zirconium dioxide’s struc-
ture upon substituting di- and trivalent metal cations
and cationic vacancies for tetravalent zirconium while
modifiers can in this case act as barriers to the surface
diffusion of atoms. On the whole, we may assume that
the deposition of different modifiers or their basic
embedding large-charge cations (e.g., W6+ and W5+) constituents (e.g., residual chloride ions and OH
[14–16]. The formation of such different defect struc- groups) onto a zirconium oxyhydroxide surface can
tures when embedding heterovalent cations suggests create barriers to crystallization and the formation the
1799

1800
KUZNETSOVA et al.
equilibrated ZrO2. Studying the state of surface layers ing were refined by full-profile fitting of the calculated
XRD patterns [23].
during the formation of the metastable states of dis-
persed oxides is therefore of great interest.
The composition of surface layers was studied via
X-ray photoelectron spectroscopy (XPS) on a SPECS
spectrometer (SPECS GmbH, Germany) equipped
with a PHOIBOS HSA3500 150 MCD9 electron
energy analyzer excited by MgKα non-monochromatic
X-ray tube radiation (1235.6 eV). The spectra were
processed using the CasaXPS program; Lorentz–
Gaussian (50%) expansion was performed after sub-
tracting the Shirley nonlinear background. The rela-
tive contents of elements were determined from the
integrated XPS line intensities with regard to the cor-
responding atomic sensitivity coefficients. The bind-
ing energy scale (Eb) was calibrated using the C1s line
(285.0 0.1 eV) as an internal standard.
In this work, we present data on the effect of some
Me3+ (Al, Y, Sc, Fe, and Mn) cations on the state of a
surface layer of modified zirconium dioxide, its phase
composition, crystallite size, and structural stability
against high temperatures.
EXPERIMENTAL
Zirconium hydroxide was precipitated from a solu-
tion of zirconium oxychloride with ammonia solution
at a constant pН 9.5
0.5 with intermixing. The
resulting gel was held for 3 h, and the precipitate was
extracted by decantation, filtered, and washed with
distilled water until a negative reaction to Cl− ions in
washwater. The precipitate was dried in air and then in
an oven at 110°C for 24 h. Modification was performed
using Al3+, Y3+, Sc3+, Fe3+, and Mn2+ cations via the
co-deposition of hydroxides with additions of the cor-
responding nitrate solutions to the zirconium oxy-
chloride solution before deposition. The content of
cationic additive was 9–12 at % per the sum of Zr and
Me cations. Heat treatment of the initial and modified
zirconium hydroxide was performed in air inside a
quartz reactor at 600, 900, and 1050°C for 3 h.
In this work, Zr600 was zirconium dioxide pre-
pared through the calcination of zirconium hydroxide
at 600°C; ZrMe900 (where Me is Al, Y, Sc, Fe, and
Mn) was zirconium dioxide prepared by calcinating
cation-modified zirconium hydroxide at 900°C.
RESULTS AND DISCUSSION
Thermal Analysis
Figure 1 shows the DSC curve profiles for unmod-
ified zirconium hydroxide and zirconium hydroxide
with additions of cationic modifiers. A complex endo-
thermic effect is observed for all samples in the tem-
perature range of up to 250°C, due to dehydration with
a total mass loss of 15–20%.
The metal contents were monitored via X-ray fluo-
rescence spectroscopy (XFS) using a PANalytical
Axionmax spectrometer.
Thermal transformations of the hydroxide samples
were studied via differential scanning calorimetry
(DSC) using a Netzsch Jupiter STA 449F1 thermal
analyzer. Programmed heating of the samples was per-
formed in a corundum crucible at a rate of 10 K/min
in a dynamic air atmosphere at a flow rate of
50 mL/min.
For zirconium hydroxide without additives, the
DSC curve reveals, along with the indicated low-tem-
perature endo-effect, a pronounced exothermic effect
without mass variation at a temperature of 442°C, due
to crystallization of the oxide phase. The exothermic
effect is 129 J/g, i.e., close to the literature’s heat crys-
tallization data of 120 [24] and 146 J/g [25]. Heating
the sample to 1000°C had no noticeable effect on the
DSC curve.
The phase composition of the oxides was investi-
gated by means of X-ray diffraction (XRD). X-ray dif-
fraction patterns were obtained in CuKα radiation on
an X’Pert PRO diffractometer with a PIXcel (PANa-
lytical) detector equipped with a graphite monochro-
mator. The range of photography was 5° to 70° on the
2θ scale with a step of 0.026°. The phases were identi-
fied using the JCPDS X-ray database. The crystallite
sizes were determined according to Debye and Scher-
rer from the broadening of small-angle reflections (d =
3.16 Å for the monoclinic (m-ZrO2) modification, d =
2.96 Å for the tetragonal (t-ZrO2) modification, and
d = 2.93 Å for the cubic (c-ZrO2) modification). The
X-ray diffraction patterns were quantitatively pro-
cessed using the Origin software package. The frac-
tions of metastable zirconium dioxide modifications
were calculated from the peak areas with interplanar
spacings of 3.16 Å for m- and 2.96 and 2.93 Å for
t(c)-ZrO2. The unit cell parameters and line broaden-
The modification of zirconium hydroxide by Y and
Sc cations increased the temperature of crystallization
by 8–10°C, compared to the unmodified sample (Fig. 1).
Upon the embedding of Fe, Mn, and Al cations, the
temperature of crystallization grew more substantially,
especially for Al (by 184°C). In the ZrMn sample, the
exothermic effect at 240–280°C was caused by the
oxidation of divalent manganese cations.
It should be noted that only one exo-effect related
to the crystallization process was observed in the DSC
curves of modified zirconium hydroxide, indicating
that the cationic modifiers interact with zirconium
hydroxide as early as the stage of hydroxide precursor
preparation. Additions from all of the cations (espe-
cially Al) slow down the crystallization process.
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STRUCTURAL PROPERTIES AND STATE OF A ZIRCONIUM DIOXIDE SURFACE LAYER
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Al
Y
Sc
628
ZrAl
240−280
nm
1050°C
900°C
562
518
453
ZrMn
ZrFe
Mn
Fe
Al
Y
Sc
nm
ZrY
452
ZrSc
Zr
442
Mn
Fe
Al
Y
Sc
nm
0
200
400
600
800
1000
T, °C
600°C
0
20
40
60
80
100
Fig. 1. DSC curves for the initial zirconium hydroxide and
zirconium hydroxide modified by Sc, Y, Al, Fe, and Mn
cations.
t-ZrO2 fraction, rel. %
Fig. 2. Fraction of metastable zirconium dioxide obtained
via the calcination of zirconium hydroxide modified by Sc,
Y, Al, Fe, and Mn cations (nm is unmodified zirconium
hydroxide) at 600, 900, and 1050°С.
X-ray Diffraction Analysis
According to the XRD data, mainly monoclinic
ZrO2 formed upon the heat treatment of unmodified
hydroxide at 600 and 900°C; the fraction of the tetrag-
onal form was 10–12 rel %.
formation depends on a the means of preparation, due
apparently to the nonequilibrium state of zirconium
dioxide.
The phase composition of the cationic-modified
samples was determined by both the nature of the cat-
ions and temperature of oxide phase formation (Fig. 2).
At 600°C, regardless of the type of cation, a metastable
tetragonal and/or cubic ZrO2 modification mainly
formed. It should be noted that clear identification of
these metastable forms is complicated by the similarity
between XRD patterns and the considerable broaden-
ing of the peaks. At 900°C, the metastable modifica-
tion was retained in the samples containing Sc, Y, and
Al cations, while those with Fe and Mn additives con-
tained mainly the monoclinic form; the t-ZrO2 frac-
tion was smaller than 12% (Fig. 2). Small amounts of
the individual Fe2O3 and Mn2O3 oxide phases of the
modifiers were also observed in the XRD patterns of
the samples with Fe and Mn additions.
Based on the results from full-profile analysis, we
determined the t-ZrO2 unit cell parameters for differ-
ent cationic-modified samples. The obtained values
and the t-ZrO2 unit cell volumes calculated from them
are given in Table 2. It can be seen that the different
ways in which cations are embedded affects the cell
parameters. More specifically, parameters a = b
increase and parameter c decreases (Table 2). In this
Table 1. (111) interplanar spacings in ZrO2 as a function of
the cationic modifier and temperature of calcination
Sample code
hkl (111), nm
Zr600
0.2947
0.2937
0.2954
0.2935
0.2930
0.2933
0.2951
0.2937
0.2952
0.2941
Thorough analysis of the XRD patterns shows that
the embedding of cations changes the (111) interplanar
spacing in the t-ZrO2 structure (Table 1) according to
ZrSc600
ZrY600
ZrAl600
ZrFe600
ZrMn600*
Zr900
ZrSc900
ZrY900
ZrAl900
the radii of cations (Zr4+ = 0.84, Y3+ = 1.02, Al3+
=
0.53, Sc3+ = 0.83, Fe3+ = 0.78, and Mn3+ = 0.65 Å
[26]). Our results testify to the formation of solid solu-
tions. It is noteworthy that the literature data for the
Y2O3–ZrO2 system [27, 28] show that the type of ZrO2
crystal structure depends on the yttrium content: as
the yttrium content increases, crystallization shifts
toward the cubic modification. At the same time, the
concentration boundary of the preferential c-ZrO2
* Mn content, 4 at %.
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KUZNETSOVA et al.
Table 2. Variation in the t-ZrO2 unit cell parameter, caused
scandium cations, due apparently to the thermal sta-
by the type of cationic modifier
bility of t-ZrO2-based solid solutions.
V × 10−3
,
nm3
Sample
а, nm
b, nm
с, nm
State of ZrO2 Surface Layers
For the initial zirconium dioxide obtained through
the heat treatment of hydroxide at 600 and 900°C, two
components were identified in the Zr3d5/2 spectral
line. An intense peak with a binding energy of 182.4 eV
characterized Zr4+ in ZrO2 [29]. The embedding of Sc,
Y, and Al cations slightly (by 0.2 eV) increased the
binding energy of this component (Fig. 3). An inverse
shift (i.e., a 0.2–0.3 eV reduction in the binding
energy) was observed upon modification by Fe and
Mn cations.
Zr600
ZrY600
0.3591(1) 0.3591(1) 0.5199(2) 67.04
0.3630(1) 0.3630(1) 0.5119(5) 67.45
ZrAl600 0.3602(1) 0.3602(1) 0.5075(3) 65.845
Zr900
ZrY900
0.3598(5) 0.3598(5) 0.5192(1)
0.3617(3) 0.3617(3) 0.5156(6)
67.22
67.47
ZrAl900 0.3601(2) 0.3601(2) 0.5078(3) 65.847
Table 3. Modified zirconium dioxide crystallite sizes
t-ZrO2 crystallite size, nm
Т, оС
A small peak at the lower binding energy of 180.9–
181.3 eV was attributed to the partially reduced zirco-
nium state Zr(4 − x)+ observed in a number of XPS and
ESR studies and explained by the presence of oxygen
vacancies in the coordination environment of zirco-
nium cations [30–34].
ZrO2
Sc
Y
Al
Fe
Mn
600 22-m
900 35-m
12
42
15
27
14
15
14
17
35-m
14
83-m
Upon the embedding of modifiers, the Zr(4 − x)+
fraction grew relative to unmodified ZrO2 by a factor
of 1.5–2, which can be explained by an increase in the
number of oxygen vacancies during incorporation of
the Me3+ cations into the lattice. In the homophase
solid solution samples, the observed fraction of
reduced Zr(4 − x)+ cations fell when the temperature of
calcination was raised to 900 and 1050°C (Table 4),
due possibly to their distribution in the volume of
grown crystallites.
1050 52-m
84
83
26-m
—
—
Here, Т is the calcination temperature and m corresponds to the
monoclinic zirconium dioxide phase.
case, the t-ZrO2 unit cell volume changes in accor-
dance with the size of the cationic modifier.
The thermal stability of solid solutions is deter-
mined by the nature of the cationic modifier. In our
iron- and manganese-containing samples, the solid
solution decomposed upon raising the temperature of
calcination to 900°C; in the samples modified with
aluminum cations, it decomposed at 1050°C. The
yttrium- and scandium-containing samples are stable
up to 1050°C (Fig. 2).
Four components were identified in expanding the
O1s spectrum, (Fig. 4). The most intense peak with a
binding energy of 530.4 eV corresponds to oxygen in
zirconium dioxide, which is consistent with the litera-
ture data [29]. Regardless of the temperature of oxide
phase formation, the embedding of Sc, Y, or Al cations
changes the energy of the O1s bond only slightly; when
modified by Fe and Mn cations, the energy of the O1s
bond falls by 0.3 and 0.5 eV, respectively.
The size of t-ZrO2 crystallites formed at 600°C was
virtually independent of the type of cationic modifier
and totaled 12–15 nm (Table 3). As the temperature of
oxide phase formation was raised to 900°C, the crys-
tallite size grew for all our samples, except the one
containing aluminum. At 1050°C, the size of t-ZrO2
crystallite in the homophase scandium and yttrium-
containing solid solutions grew to 83–84 nm and
exceeded the critical size (30 nm) of the tetragonal zir-
conium dioxide stability [20]. In the aluminum-con-
taining heterophase samples prepared at 1050°C,
monoclinic zirconium dioxide with a crystallite size of
26 nm predominated (Table 3).
The emergence of other, lower-intensity compo-
nents could be due to different causes, including struc-
tural inhomogeneity (528.7–529.1 eV) and the pres-
ence of residual OH-groups and/or adsorbed oxygen
species (532.4–532.7) [35]. The component with a
binding energy of 531.3–531.7 eV could characterize
oxygen with reduced negative charge Oδ−, which was
observed in [35] for yttrium-stabilized zirconium
dioxide and was defined as nonlattice [35]. It can be
seen in Table 4 that the fraction of this component
grows by a factor of 2–4, depending on the type of cat-
ion modifier. Interestingly, a symbate change in the
content of reduced zirconium cations and nonlattice
form of oxygen is observed. This could be due to the
formation of oxygen vacancies in the anionic sublat-
A 600°C, additions of cationic modifiers thus sta-
bilized the nonequilibrium dispersed form of zirco-
nium dioxide. In this case, both stabilization factors
were at work: the size effect and formation of modifier
solid solutions in ZrO2. At high temperatures (over
1000°C), the effective stabilizers were yttrium and tice of zirconium dioxide.
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STRUCTURAL PROPERTIES AND STATE OF A ZIRCONIUM DIOXIDE SURFACE LAYER
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Zr3d5/2, 3/2
Zr3d5/2, 3/2
(a)
(b)
O1s
O1s
(a)
(b)
ZrMn
ZrMn
ZrFe
ZrAl
ZrFe
ZrFe
ZrAl
ZrY
ZrAl
ZrAl
ZrY
ZrY
ZrY
ZrSc
ZrSc
ZrSc
Zr
ZrSc
Zr
Zr
Zr
188 186 184 182 180 178 188 186 184 182 180 178
Binding energy, eV Binding energy, eV
536 534 532 530 528 526 536 534 532 530 528 526
Binding energy, eV Binding energy, eV
Fig. 3. XP spectra of Zr3d for the zirconium hydroxide
samples modified by Sc, Y, Al, Fe, and Mn cations at
(a) 600 and (b) 900°С.
Fig. 4. XP spectra of O1s for the zirconium hydroxide sam-
ples modified by Sc, Y, Al, Fe, and Mn cations at (a) 600
and (b) 900°С.
In studying the XP spectra of the cationic modifi-
ers, we established that the Sc2p scandium spectrum
(Fig. 5) is represented by the doublet Sc2p3/2 and
Sc2p1/2. The Sc2p3/2 spectrum contained one peak
with a binding energy of 402.2–402.3 eV, which is
higher than the Sc2p3/2 binding energy in Sc2O3
The binding energy in Fe2p3/2 was 710.8–711.1 eV,
which is most similar to the Fe2p3/2 binding energy in
Fe2O3 (711.0–711.1 eV) [39, 40] (Fig. 5). As we estab-
Table 4. Contents of the extracted component in XP spec-
(401.3–401.9 eV [29]). Both our data and the literature tra of Zr3d and O1s in the homophase zirconium dioxide
samples as functions of the type of cation and temperature
of calcination
[36, 37] show that zirconium dioxide modified by
scandium cations is a solid solution of Sc3+ cations in
zirconium dioxide. We may assume that the increase
in the Sc2p3/2 binding energy, compared to individual
Sc2O3, is related to the change in the chemical envi-
ronment of scandium, due to the incorporation of
scandium cations in the zirconium dioxide lattice.
Content, rel. %
Sample
Zr(4 − x)+
Оδ–
Zr600
11.9
27.2
37.3
32.3
20.8
12.9
11.0
14.7
15.9
17.7
14.5
14.9
2.6
5.9
8.4
9.9
5.8
4.2
2.4
6.5
5.5
6.8
14.6
14.2
ZrSc600
ZrY600
ZrAl600
ZrFe600
ZrMn600*
Zr900
The yttrium spectrum is represented by a Y3d5/2,3/2
doublet with a spin-orbit splitting of 1.9 eV. In the con-
sidered sample, the Y3d5/2,3/2 binding energy was
157.5–157.6 eV, higher than that of the Y3d5/2,3/2 com-
ponent in Y2O3 (156.4–157.0 [29]). The established
binding energy typical of yttrium in the zirconium
dioxide-based substitutional solid solution was
observed in the Y2О3–ZrO2 oxide films in [38]. Our
result was consistent with the XRD data.
ZrSc900
ZrY900
ZrAl900
ZrSc1050
ZrY1050
For Al2p, we observed a broad spectrum both at
600 and at 900°С with a binding energy of 74.0–
74.5 eV, which is similar to the aluminum binding
energy in the individual oxide [29] (Fig. 5).
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KUZNETSOVA et al.
It can be seen that regardless of the temperature of
Fe2p
calcination, the content of modifier on the surface was
similar to the one in the bulk in the samples modified
by scandium and yttrium cations. Considerable sur-
face enrichment was observed in the samples modified
by aluminum, iron, and manganese cations. The
observed distribution of cationic modifiers between
the surfaces and volumes apparently determined the
thermal stability of the solid solutions. The solid solu-
tions (Al-, Fe-, and Mn–ZrO2) in which the modifi-
ers were mainly distributed on the surface were less
stable. In contrast, the Y- and Sc–ZrO2 samples with
uniform volume–surface distributions were character-
ized by high thermal stability of the metastable ZrO2-
based solid solutions with crystallite sizes much larger
than the critical value.
900°C
600°C
730 725 720 715 710 705
Al2p
900°C
600°C
78 77 76 75 74 73 72 71
Y3d
1050°C
900°C
600°C
162 160 158 156 154
CONCLUSIONS
Sc2p
During the formation of the oxide phase at 600°С,
embedding of the considered cationic modifiers stabi-
lize the tetragonal zirconium dioxide modification.
According to the XRD and XPS data, the synthesized
samples were solid solutions of Me3+ cations in tetrag-
onal zirconium dioxide. It follows from the XRD and
DSC data that the embedding of cations slows crystal-
lization and stabilizes the oxide phase crystallite size at
a level of 12–15 nm. Our results show that at relatively
low temperatures, both factors of the stabilization of
nonequilibrium zirconium dioxide modifications, i.e.,
the size effect and formation of the solid solutions, are
important.
1050°C
900°C
600°C
410 408 406 404 402 400 398
E, eV
Fig. 5. XP spectra of Sc 2p, Y 3d, Al 2p, and Fe 2p for the
samples of modified zirconium hydroxide obtained at 600,
900, and 1050°С.
As the calcination temperature grows to 900°C,
solid solutions containing iron and manganese
decompose, and a mainly stable monoclinic zirco-
nium dioxide modification forms. The Al, Sc, and Y
cations effectively stabilize metastable zirconium
dioxide-based solid solutions. The highest thermal
stability (up to 1050°С) is typical of solid solutions
containing Sc and Y cations.
Upon an increase in the calcination temperature in
the Sc- and Y-containing samples, the crystallite size
grows to 84 nm, which is much higher than the critical
value; meanwhile, according to the XPS data, the cat-
ions are uniformly distributed between the volume and
surface. In these samples, the metastable ZrO2 modi-
fication apparently exhibits high stability, due to the
thermal stability of the homogeneous solid solution of
cationic modifiers in zirconia; the size factor does not
play a decisive role in this case.
Upon modification by Al cations, the size of meta-
stable ZrO2 crystallites does not change upon an
increase in the temperature of oxide phase formation
(up to 900°С). The content of cations on the surface is
in this case considerably higher than in the bulk; i.e.,
the Al cations form a surface solid solution in zirco-
nium dioxide that prevents sintering and stabilizes the
crystallite size at a level of 14–15 nm. At a higher tem-
lished in [41] by means of XPS, manganese cations in
the Mn–ZrO2 samples calcined at 600°С were in oxi-
dation state 4+ ≥ n ≥ 2+, mainly when n = 3+.
Our XPS and XRD data showed that the alumi-
num, iron, and manganese cations were ordered (dis-
tributed nonstatistically) in the zirconium dioxide lat-
tice in the form of separate clusters, in which the state
of the cation was similar to the one in oxides.
The determined relative metal concentrations on
the surface (XPS) and in the bulks (XFS) of the
homophase t-ZrO2 solid solution-based samples are
given in Table 5.
Table 5. Ме/Zr + Ме atomic ratio according to the XPS
and XFS data (Т is calcination temperature)
XPS
XFS
Т, оС
Sc
Y
Al Fe Mn Sc
Y
Al Fe Mn
600 0.11 0.12 0.26 0.15 0.08 0.12 0.13 0.09 0.09 0.04
900 0.13 0.14 0.23
1050 0.14 0.12
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—
—
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RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A
Vol. 92
No. 9
2018

STRUCTURAL PROPERTIES AND STATE OF A ZIRCONIUM DIOXIDE SURFACE LAYER
1805
18. P. N. Kuznetsov, L. I. Kuznetsova, A. M. Zhyzhaev,
perature (1050°С), the solid solution decomposes; this
is accompanied by the phase transition of t-ZrO2 to
the stable monoclinic modification.
et al., Appl. Catal., A 227, 299 (2002).
19. O. V. Pozhidaeva, E. N. Korytkova, D. P. Romanov,
and V. V. Gusarov, Russ. J. Gen. Chem. 72, 849 (2002).
20. R. C. Garvie, J. Phys. Chem. 69, 1238 (1965).
REFERENCES
1. O. V. Al’myasheva, B. A. Fedorov, A. V. Smirnov, and
V. V. Gusarov, Nanosist.: Fiz., Khim. Mat. 1 (1), 26
(2010).
21. G. D. Yadav and J. J. Nair, Microporous Mesoporous
Mater. 33, 1 (1999).
22. K. Arata, Appl. Catal., A 146, 3 (1996).
23. A. le Bail, Y. Gao, J. L. Fourquet, and C. Jacoboni,
2. N. K. Oh, J. T. Kim, G. Kang, et al., Appl. Surf. Sci.
Mater. Res. Bull. 25, 831 (1990).
394, 231 (2017).
24. D. G. Barton, S. L. Soled, G. D. Meitzner, et al.,
3. J. D. Fidelus, W. Lojkowski, D. Millers, et al., Solid
J. Catal. 181, 57 (1999).
State Phenom. 128, 141 (2007).
25. A. Kaddouri, C. Mazzocchia, E. Tempesti, and
4. M. Mamak, N. Coombs, and G. A. Ozin, Chem.
R. Anouchinsky, J. Therm. Anal. 53, 97 (1998).
Mater. 13, 3564 (2001).
26. R. D. Shannon and C. N. Prewitt, Acta. Crystallogr.
5. V. V. Popov and A. A. Pisarev, Materials and Processes
of Production of Thermal Barrier Coating (NIYaU MIFI,
Moscow, 2016) [in Russian].
6. H. Th. Rijnten, in Physical and Chemical Aspects of
Adsorbents and Catalysts, Ed. by B. G. Linsen (Aca-
demic, London, New York, 1970; Mir, Moscow, 1973).
7. P. N. Kuznetsov, L. I. Kuznetsova, and A. M. Zhizhaev, in
Fundamental Principles of Mechanochemical Activation,
Mechanosynthesis and Mechanochemical Technologies,
Ed. by V. V. Boldyrev et al., Vol. 19 of Integration Proj-
ects of Siberian Branch of RAS (Sib. Otdel. RAN, Novo-
sibirsk, 2009), pp. 68–86 [in Russian].
8. P. N. Kuznetsov, L. I. Kuznetsova, V. P. Tverdokhle-
bov, and A. L. Sannikov, Khim. Tekhnol., No. 2, 7
(2005).
26, 925 (1969).
27. R. G. Silver, C. J. Hou, and J. G. Ekerdt, J. Catal. 118,
400 (1989).
28. X. Bokhimi, A. Morales, A. Garcia-Ruiz, et al., J. Solid
State Chem. 142, 409 (1999).
29. C. D. Wagner, J. F. Moulder, L. E. Davis, and
W. M. Riggs, Handbook of X-ray Photoelectron Spec-
troscopy (Perking-Elmer, Eden Prairie, MN, 1979).
30. W. Wang, S. Hu, Y. Han, et al., Surf. Sci. 653, 205
(2016).
31. M. Chun, M. J. Moon, J. Park, and Y. C. Kang, Bull.
Korean Chem. Soc. 30, 2729 (2009).
32. G. M. Ingo and G. Marletta, Nucl. Instrum. Methods
Phys. Res., Sect. B 116, 440 (1996).
33. C. Morant, J. M. Sanz, L. Galan, et al., Surf. Sci. 218,
9. A. V. Ivanov and L. M. Kustov, Ross. Khim. Zh. 44, 21
331 (1989).
(2000).
34. A. F. Bedilo, M. A. Plotnikov, N. V. Mezentseva, et al.,
10. Nanomaterials: Properties and Perspective Applications,
Ed. by A. B. Yaroslavtsev (Nauchnyi Mir, Moscow,
2015) [in Russian].
11. A. V. Smirnov, B. A. Fedorov, M. V. Tomkovich,
O. V. Al’myasheva, and V. V. Gusarov, Dokl. Phys.
Chem. 59, 71 (2014).
Phys. Chem. Chem. Phys. 7, 3059 (2005).
35. S. Ntais, R. J. Isaifan, and E. A. Baranova, Mater.
Chem. Phys. 148, 673 (2014).
36. D. W. Strickler and W. G. Carlson, J. Am. Ceram. Soc.
48, 286 (1965).
37. H. Fujimori, M. Yashima, M. Kakihana, and
12. M. J. Mayo, A. Suresh, and W. D. Porter, Rev. Adv.
M. Yoshimura, J. Am. Ceram. Soc. 81, 2885 (1998).
Mater. Sci. 5, 100 (2003).
38. K. S. Jeong, J. Song, D. Lim, et al., Appl. Surf. Sci.
13. G. K. Karagedov, S. S. Shatskaya, and N. Z. Lyakhov,
320, 128 (2014).
Khim. Inter. Ustoich. Razvit. 14, 369 (2006).
39. M. Muchler, R. Schlogl, and G. Erlt, J. Catal. 138, 413
14. A. B. Yaroslavtsev, Solid State Chemistry (Nauchnyi
(1992).
Mir, Moscow, 2009) [in Russian].
40. T. Yamashita and P. Hayes, Appl. Surf. Sci. 254, 2441
15. P. N. Kuznetsov, A. V. Kazbanova, L. I. Kuznetsova,
(2008).
et al., React. Kinet. Mech. Catal. 113, 69 (2014).
41. L. I. Kuznetsova, A. V. Kazbanova, Yu. L. Mikhlin,
A. M. Zhizhaev, and P. N. Kuznetsov, Russ. J. Phys.
Chem. A 84, 1939 (2010).
16. M. A. Cortes-Jacome, C. Angeles-Chavez, and
E. Lopes-Salinas, Appl. Catal., A 318, 178 (2007).
17. L. G. Karakchiev, E. G. Avvakumov, O. B. Vinokurova,
A. A. Gusev, and N. Z. Lyakhov, Russ. J. Inorg. Chem.
48, 1447 (2003).
Translated by E. Bondareva
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A Vol. 92 No. 9 2018