Preparation, morphology, and luminescent properties of europium-doped nanodispersed scandium sesquioxide

Article abstract of DOI:10.1134/S0036023612120030

Scandium sesquioxide-based solid solutions of composition Sc _{2 - 2x} Eu_2x O₃ (0.005 ≤ x ≤ 0.05) were prepared by thermolysis of Sc_{1 - x} Eu _x (CH ₃COO)₃ and by reacting mixtures of scandium and europium nitrates with ethylene glycol. Thermal decomposition of Sc_{1 - x} Eu _x (CH₃COO)₃ was found to yield Sc _{2 - 2x} Eu_2x O₃ with the shapes of aggregates atypical of the cubic structure of this oxide, and the reaction products of scandium and europium nitrates were found to have a loose spongelike structure. A spectroscopic study showed that Sc_{2 - 2x} Eu_2x O ₃ and Sc_{1 - x} Eu _x (CH₃COO) ₃ are potential luminescent materials active in the visible spectral region. The tervalent europium in the Sc_{2 - 2x} Eu_2x O ₃ structure is the source of strong red emission (⁵ D ₀ → ⁷ F ₂) and can be used in fluorescent lamps, colored lightning, and optoelectronic devices.

Full text of DOI:10.1134/S0036023612120030

ISSN 0036ꢀ0236, Russian Journal of Inorganic Chemistry, 2012, Vol. 57, No. 12, pp. 1529–1534. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © I.V. Baklanova, V.N. Krasil’nikov, L.A. Perelyaeva, O.I. Gyrdasova, 2012, published in Zhurnal Neorganicheskoi Khimii, 2012, Vol. 57, No. 12, pp. 1627–1633.
SYNTHESIS AND PROPERTIES
OF INORGANIC COMPOUNDS
Preparation, Morphology, and Luminescent Properties
of EuropiumꢀDoped Nanodispersed Scandium Sesquioxide
I. V. Baklanova, V. N. Krasil’nikov, L. A. Perelyaeva, and O. I. Gyrdasova
Institute of SolidꢀState Chemistry, Ural Branch, Russian Academy of Sciences,
ul. Pervomaiskaya 91, Yekaterinburg, 620990 Russia
Received July 22, 2012
Abstract—Scandium sesquioxideꢀbased solid solutions of composition Sc2 – 2xEu O (0.005
≤
x
≤
0.05) were
2x 3
prepared by thermolysis of Sc1 – xEu (CH COO) and by reacting mixtures of scandium and europium
x
3
3
nitrates with ethylene glycol. Thermal decomposition of Sc1 – xEu (CH COO) was found to yield Sc2 – 2xEu O
x
3
3
2x 3
with the shapes of aggregates atypical of the cubic structure of this oxide, and the reaction products of scanꢀ
dium and europium nitrates were found to have a loose spongelike structure. A spectroscopic study showed
that Sc2 – 2xEu O and Sc1 – xEu (CH COO) are potential luminescent materials active in the visible spectral
2x
3
x
3
3
region. The tervalent europium in the Sc2 – 2xEu O structure is the source of strong red emission (5D0
→
7
F2)
2x 3
and can be used in fluorescent lamps, colored lightning, and optoelectronic devices.
DOI: 10.1134/S0036023612120030
Scandium sesquioxide (Sc O3), which has high glycine nitrate method is very attractive for preparing
2
thermal conductivity, mechanical strength, and radiaꢀ nanostructured sesquioxide Sc2 – 2xLn O3; the underꢀ
2x
tion stability, is a promising material for manufacturꢀ lying idea of this method is the reaction of mixtures of
ing highꢀpower solid laser matrices, laser displays, scandium and lanthanide nitrates with glycine at relaꢀ
optical amplifiers, cathode ray tubes, and other tively low temperatures [2]. An interesting variant of
devices [1–15]. A special advantage of Sc O3 over this method is where the combustible agent is ethylene
2
Y2O3 (which is widely used in the manufacture of optiꢀ glycol; this method was employed to prepare nanodisꢀ
cally active materials, in particular, luminescent mateꢀ persed oxides, namely, CeO [19], Lu Eu O [20]
2
2 –
x
x
3
rials [16]) consists in the chemical inertness toward the La O , Ga O3, and MgO; a solid electrolyte of compoꢀ
2
3
2
natural components of air, namely, carbon dioxide and sition La0.88Sr0.12Ga0.82Mg0.18O2.85 [21, 22]; and
water vapor. Inasmuch as it is difficult to prepare Sc O3 ytterbiumꢀdoped yttrium aluminum garnet [23].
2
and Sc2 – 2xLn O solid solutions (where Ln stands for Here, we used two original methods to prepare
2x
3
a lanthanide) in single crystals because of their very quasiꢀ1D and nanostructured europiumꢀdoped
high melting temperatures ( 2500 ), in the last years scandium sesquioxide. One method involves therꢀ
efforts have been made to prepare these oxides as molysis of Sc1 – xEu (СH COO) precursors; the
∼
°
C
x
3
3
nanosized samples, ceramics, and films. It is assumed other involves the reaction of scandium and europium
that, thanks to quantum, dimensional, and surface nitrates with ethylene glycol.
effects, the manufacture of nanosized, specifically,
quasiꢀoneꢀdimensional (1D) structures would endow
EXPERIMENTAL
the material with unique optical properties. At the
same time, nanosized Sc2 – 2 Ln O oxides can serve
x
2x
3
The Sc1 – xEu (СH COO)
3
precursor with
x
3
as precursors for manufacturing transparent highꢀ
density ceramics.
extended crystal shapes was prepared by dissolving
mixtures of Sc(OH)3 and Eu(OH)3 with a certain ratio
Of the simplest and productive methods for preparꢀ Sc/Eu in 20% acetic acid at 60 C and subsequently
°
ing highly dispersed oxide materials with a tailored concentrating the solution to dry residue on a water
aggregate morphology, the precursor method should bath. The required hydroxide mixtures were prepared
be mentioned; the underlying idea of this method is by coprecipitating the nitrates from solutions by addꢀ
the pseudomorphic transformation of the precursor to ing aqueous ammonia. The nitrate solutions were preꢀ
the oxide under heating. The most frequently used pared from Sc O3 and Eu O3 (99.95%), which were
2
2
precursors are salts of carboxylic acids. For example, precalcined at 800
°
C
for 2 h, and concentrated HNO3
nanodispersed sesquioxides Y2O3 and Sc O3 with (high purity grade). The alternative method used to
2
extended particle shapes, which are atypical of their prepare Sc1 – xEu (СH COO) involved boiling Sc O
x
3
3
2
3
cubic (isotropic) structure, were prepared as a result of and Eu O3 mixtures in 20% acetic acid followed by
2
thermolysis of yttrium and scandium acetates (which separation of acetate crystals from the mother solution
crystallize in fibrous or acicular crystals) [17, 18]. A by vacuum filtration and drying at 40°C.
1529

1530
BAKLANOVA et al.
ried out on a STADIꢀP (STOE) Xꢀray diffractometer
using Cu radiation and a POLAM Sꢀ112 polarizing
microscope in the transmitted light. Particle shapes
and particle sizes were determined by scanning
electron microscopy (SEM) using a JSM JEOL
Δ
m, mg
K
α
0
TG
6
390LA instrument. The thermogravimetric analyꢀ
1
2
0
sis of Sc1 – xEu (СH COO) precursors was performed
x
3
3
on a Qꢀ1500D derivatograph (the heating rate was
0 K/min). Raman spectra were recorded at room
temperature on a RENISHAWꢀ1000 spectrophotomꢀ
1
0
+
eter ( = 514.5 nm, Ar laser, W = 25 mW). Cathodꢀ
λ
oluminescence (CL) spectra were recorded on a
KLAVI setup [25] in the pulsed cathodoluminescence
mode, where Sc2 – 2xEu O samples having equal
DTA
2x
3
3
0
0
weights (30 mg) were exposed to shortꢀduration (2ꢀns)
electron beams with an energy of 170 keV (current denꢀ
2
sity: 160 A/cm ). Reflection spectra were recorded in
425°С
the range 190–900 nm on a UVꢀ2401 PC (Shimadzu)
spectrophotometer using a BaSO4 reference. Emission
spectra were recorded on a Varian Cary Eclipse fluorimꢀ
eter (a 75ꢀkW xenon lamp); test samples were prepared
as disks 5 mm in diameter and 2 mm thick.
4
200
400
600
800
T, °C
Fig. 1. TG and DTA curves for Sc0.95Eu0.05(СH COO)3
.
3
RESULTS AND DISCUSSION
According to microscopic analysis, Sc1 – xEux
The method used to prepare Sc2 – 2 Eu O as a
x
2x
3
(СH COO) (0
≤
x 0.1) crystals prepared by spontaꢀ
≤
3
3
nanodispersed powder involved a reaction in the redox
system where the oxidizer was a mixture of scandium
and europium nitrates and the reducer (combustible
material) was ethylene glycol. Ethylene glycol (unlike
glycine) can dissolve scandium and yttrium nitrates
neous crystallization of a saturated solution are shaped
as needles or rods with cross sections of about 0.2–
0
.5
µ
m and lengths of up to 1–5 m and tend to lonꢀ
µ
gitudinal intergrowth. The birefringence of these
crystals is very high. Refractive indices for
Sc Eu (СH COO) are as follows: Ng = 1.612,
under mild heating (40–50 C) to form a transparent
°
0
.9
0.1
3
3
gel. Upon further rise in temperature, the gel is dehyꢀ
drated with elimination of water vapor. The presence
of water in the gel is due to its occurrence in the preꢀ
cursor nitrates, which are isolated from nitric acid
solutions as crystal hydrates [24]. After the water is
Np = 1.504, Ng
composition corresponds to
–
Np = 0.108. In the samples where the
x > 0.1, shapeless flat chips
of Eu(СH COO)3 H O crystals and their random
⋅
n
2
3
intergrowths, having nonꢀuniform extinction, are
encountered along with extended Sc1 – xEu (СH COO)
x
3
3
eliminated, at temperatures above >80 C the gel starts
°
crystals.
The thermal decomposition of Sc1 – xEux
to decompose with gas bubble evolution, which
becomes progressively vigorous; then, the process
becomes uncontrollable, that is, it occurs spontaneꢀ
ously until the oxide is formed. Inasmuch as this proꢀ
cess occurs without visible nitrogen oxide evolution,
the reaction of the components of the redox system
(
СH COO)3 to Sc2 – 2xEu O occurs in one stage within
3
2x
3
the temperature range
∼
300–425 C. The weight losses of
°
Sc(СH COO)3 and Sc Eu (СH COO) samples as
3
0.95
0.05
3
3
estimated from TG curves (Fig. 1) are close to the theꢀ
oretical values calculated on the assumption of formation
of Sc O3 (68.96 wt %) and Sc Eu O (67.33 wt %), and
(
which is the dehydrated gel based on a scandium and
2
1.9
0.1
3
europium nitrate mixture and ethylene glycol) may be
described by the following equation:
amount to 68.9 and 67.25 wt %, respectively.
The SEM image in Fig. 2a demonstrates that the conꢀ
version of Sc0.975Eu0.025(СH COO)3 into Sc Eu O
(
2 − 2x)Sc
3HOCH CH OH = Sc Eu O
3
(
NO3
)
+ 2xEu
(
NO3
)
3
1.95
0.05
3
3
3
under heating in air occurs with the inheritance of the
precursor crystal shape by oxide particles. However,
aggregates of the nascent oxide are bent in the course
of the decomposition of the precursor with eliminaꢀ
tion of volatiles, likely because of the inconsistence of
the oxide cubic structure and anisotropic shapes of
aggregates and because of their constitutional specifꢀ
+
(1)
2
2
2−2x
2x
+
6CO + 3N + 9H O.
2 2 2
Dehydrated scandium and europium nitrates are
also well soluble in ethylene glycol under heating; for
this reason, reaction (1) can be carried out after the
nitrate mixture is partially or completely dehydrated.
ics. The SEM images recorded at 90000 magnification
×
The phase analysis of the precursors, their thermolꢀ show that these aggregates represent rolls of very thin
ysis products, and the products of reaction (1) was carꢀ oxide layers. Reaction (1) occurs with vigorous evolution
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 57 No. 12 2012

PREPARATION, MORPHOLOGY, AND LUMINESCENT PROPERTIES
1531
0.5
μ
m
(b)
1 μm
(а)
Fig. 2. SEM images of the sesquioxide of composition Sc1.95Eu0.05O3 prepared (a) by thermolysis of Sc0.975Eu0.025(СH COO)
3
3
and (b) by heating the nitrate mixture with ethylene glycol. In the inset: a SEM image of Sc0.975Eu0.025(СH COO)3 precursor
3
crystals.
of gaseous products (CO , N2, and H O), and this dicꢀ
Europium(III) in the Sc O3 cubic structure can subꢀ
2
2
2
tates the morphology of the nascent Sc2 – 2xEu O3. From stitute two positions ( 2
C
and C3i) in the ratio C2
/C3i = 3 : 1
2x
3
+
the SEM image in Fig. 2b, one can see that the sesquiꢀ [16]. Electric dipole transitions are allowed for Eu
oxide of composition Sc1.95Eu0.05O3, which was preꢀ ions in the C2 positions, whereas the transitions from
pared by reacting scandium and europium nitrates the C3i positions are forbidden. When europium ions
with ethylene glycol, has a loose spongelike structure are in the C3i positions, magnetic dipole transitions are
and is built of very thin nanoparticles. This agrees with observed.
the absence of distinct reflections in the Xꢀray diffracꢀ excited state to the FJ lowerꢀlying states (
4
f
→
4f emission bands due to transitions from
7
J
= 0, 1, 2, 3, or
3+
–1
tion pattern of this sample, caused by its Xꢀray amorꢀ 4) in the Eu ion appear in the range 2000–5000 cm .
–
1
phous state. The crystallization of the Xꢀray amorꢀ
phous phase to cubic Sc Eu O occurs as a result of
(611 nm), which is the strongest
The line at 3086 cm
–1
1.9
0.1
3
line in the spectrum, and the line at 3702 cm (635 nm)
correspond to the 5D0
→
7
F2 transition in an Eu ion
3+
annealing the sample at temperatures above >700
°
C.
For the Sc Eu O sample after annealing the product
1.95
0.05
3
in the C2 position [16]. Three weaker bands at 2373
586), 2601 (594), and 2805 cm (601 nm) are associꢀ
ated with transitions from the D0 level to F1 Stark levꢀ
els in an Eu ion in the C2 position. The weak line at
2283 cm (582 nm) may be identified as D0
magnetic dipole transition of an Eu ion in the C3i
position. The luminescence line at 2212 cm (580
of reaction (1) at 800
°
C
for 2 h, the average crystallite size
–1
(
estimated according to Scherrer was 12.3 nm. The difꢀ
5
7
fraction pattern for the Sc Eu O sample prepared
3+
1.9
0.1
3
by heating Sc Eu (СH COO) at 500
°
C
has very
–1
5
7
→
0.95
0.05
3
3
F1
broad lines and a large background, which is another piece
of evidence for the high dispersity of the sample. Figure 3
displays Xꢀray diffraction patterns for Sc Eu O samꢀ
3+
–1
1.9
0.1
3
nm) of the magnetic dipole transition is related to a
ples prepared by heating Sc0.95Eu0.05(СH COO)3 to
more intense 5D0
7
3+
3
→
F0 transition of an Eu ion in the
5
00, 900, and 1100
°
C
at a rate of 10 K/min followed
–1
C2 position. The lowꢀintensity line at 4040 cm (649
nm) corresponds to the D0
by 2ꢀh exposures at these temperatures.
5
7
→
F3 transition, and that
–
1
5
7
→
at 4924 cm (689 nm) corresponds to the D0
F4
→
Raman spectra of Sc2 – 2xEu O solid solutions
2x
3
transition. Noteworthy, the probability of the 5D0
prepared by the two aboveꢀdescribed methods were
recorded at = 514.5 nm. This excitation (which is
closed to the excitation of the F0
7
F1 magnetic dipole transition (orange) is almost indeꢀ
λ
7
5
pendent of the local surrounding of the europium in
→
D1 transition
the host. The 5D0
→
7
F2 transition (red) has an electric
3+
(
λ
ex
= 525 nm) in Eu [26]) gives rise to a very active
dipole nature, is very sensitive to the europium ion surꢀ
rounding, and is characterized as hypersensitive. The
emission spectrum of europium(III) (Fig. 4). Espeꢀ
cially noteworthy is the Raman spectrum of the
х
=
.025 sample, where europium luminescence comꢀ transition intensity ratio 5
D
0
→
7
F /
2
5
D
7
→
F
1
is the
0
0
pletely suppresses the Raman spectrum of Sc O3. The asymmetry ratio. The higher the ratio, the closer the
2
3+
lines observed in the Raman spectra of Sc1.95Eu0.05O3 local symmetry of the Eu ion to a center of inversion.
3+
samples synthesized by the two methods coincide in This ratio indicates the deviation of the Eu ion from,
their positions regardless of the preparation method; or approaching to, centrosymmetric geometry as
that is, the macrostructure of these samples is the same regards its first coordination sphere. The asymmetry
Fig. 5). Insignificant differences in line intensities ratio in favor of the 5D0
→
7
F2 transition and the occurꢀ
(
5
7
can arise from the different degrees of crystallinity of rence of the forbidden transition D0
→
F0 (580 nm)
the samples. are indicative of an asymmetric local surrounding of
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 57 No. 12 2012

1532
BAKLANOVA et al.
I
1
×
10–4
4
2
1
2
0
8
6
4
2
1
3
2
3
1
0
1000
2000
3000
4000
5000
Δν, cm
–
1
Fig. 4. Raman spectra of Sc2 – 2xEu O oxides where
x
=
2
x 3
(
1) 0.01, (
2) 0.025, and (3) 0.05, prepared by thermolysis
of the Sc1 – xEu (СH COO) precursor.
x
3
3
1
not observed in emission spectra for the specified exciꢀ
tation wavelength. The nonappearance of the line corꢀ
5
7
responding to the D0
→
F0 transition indicates that
Eu ions occupy both possible positions ( 2 and C3i
in the scandium oxide lattice. The strongest emission
is observed for the Sc2 – 2xEu O sample where
3+
C
)
х
=
2x
3
2
0
30
40
, deg
50
60
0.025; up to х = 0.05, a wellꢀknown effect of concenꢀ
2θ
tration quenching of luminescence is observed, which is
related to the transverse relaxation mechanism (Fig. 6).
As the europium concentration increases, distances
Fig. 3. Xꢀray diffraction patterns of Sc1.9Eu0.1O3 samples
prepared by heating Sc0.95Eu0.05(СH COO) to 500, 900,
and 1100
3
3
3+
°
C
at a rate of 10 K/min followed by exposure at
between Eu ions (Eu–O–Sc bonds in the solid soluꢀ
tion) become shorter and the crossꢀrelaxation rate
becomes higher, thereby decreasing luminescence
intensity. Luminescence quenching can likewise arise
from the increasing intensity of radiationless transiꢀ
these temperatures for 2 h.
the europium ion and of the preferred occurrence of
europium ions in the C2 positions. Luminescence from
levels higher than D0 is not observed because of rapid
radiationless relaxation to the D0 level.
7
3+
tions to lower FJ levels of Eu
.
5
Pulsed cathodoluminescence appeared very sensitive
5
3+
to the occurrence of Eu cations in Sc2 – 2xEu O [26].
2x
3
Strong lines in the reflection spectra for quasiꢀ In the CL spectrum of a Sc1.95Eu0.05
O
sample prepared
COO) precurꢀ
3
oneꢀdimensional Sc2 – 2xEu O (
x
= 0.01, 0.025, by thermolysis of the Sc0.975Eu0.025(СH
3
3
2
x
3
0
.05) solid solutions, prepared by thermolysis of sor, there are nine lines of various intensities, which
5 7
→
Sc1 – xEu (СH COO) , correspond to 7F0
→
5
L6 (394 correspond to the
3+
D
0
F (J = 0, 1, 2, 3, or 4) tranꢀ
J
x
3
→
3
7
5
nm), and F0
internal configurational
D2 (465 nm) transitions and relate to sitions of the Eu ion (Fig. 7). With highꢀenergy exciꢀ
3+
4
f
–4
f
transitions of Eu in tation, the CL spectra for Sc1.95Eu0.05
O feature the
3
3
+
same radiation transitions as in the Raman spectra of
Sc O3. Figure 6 is the Eu emission intensity versus
2
+
Sc2 – 2 Eu O (Figs. 4, 5) excited by an Ar laser ( =
λ
concentration plot with excitation with
λ
ex
= 394 nm
x
2x
3
514.5 nm).
in the range 550–800 nm. The emission spectra are
dominated by an active line at 613 nm, which belongs
Noteworthy, europiumꢀdoped scandium acetate
5
7
to the D0
corresponds to the D0
sion lines at 591 nm (5D0
europium ion occupies a noncentrosymmetric posiꢀ of 315–400 nm, Sc1 – xEu (СH COO) powders show a
→
F2 transition. A weaker line at 701 nm also has interesting optical properties, namely, lumiꢀ
5
7
→
F4 transition. Weak emisꢀ nescence in the visible spectral region. When exposed to
7
→
F1) prove that the the light of a domestic UV lamp with a wavelength range
x
3
3
5
7
tion in the Sc O structure. The D0
→
F3 transition is bright red luminescence with an intensity increasing in
2
3
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 57 No. 12 2012

PREPARATION, MORPHOLOGY, AND LUMINESCENT PROPERTIES
1533
I
1
×
10–4
I
300
4
1
2
0
8
6
4
2
0
2
1
2
00
00
0
1
3
1
1
2
600
700
800
, nm
λ
2
000
3000
4000
5000
Δν, cm–1
Fig. 5. Raman spectra Sc1.95Eu0.05O3 samples synthesized
) by thermolysis of the Sc1.95Eu0.05(СH COO) precurꢀ
(
1
Fig. 6. Emission spectra of Sc2 – 2xEu O solid solutions
2x 3
where x = (1) 0.01, (2) 0.025, and (3) 0.05).
3
3
sor and (
2) by reaction (1).
response to increasing europium concentration. Reflecꢀ Sc2 – 2xEu O (0.005
≤
x
≤
0.05) solid solutions with
2x
3
tion spectra for all Sc1 – Eu (СH COO) samples feaꢀ
ture two strong lines, which are associated with interꢀ
x
x
3
3
anisotropic shapes of aggregates which are atypical of
the cubic structure of this oxide. Reacting the compoꢀ
nents of the redox system that consists of a mixture of
scandium and europium nitrates (the oxidizer) and ethꢀ
ylene glycol (the reducer), we prepared nanodispersed
3
+
nal configurational
4
f
–4
f
transitions of Eu in the
7
5
7
host and correspond to F0
→
L6 (394 nm) and F0
D2 (465 nm) transitions. An Eu ion has a low
→
5
3+
5
5
excited level ( D0) of the
lies below the f5
configuration, and this gives rise to Sc2 – 2
very narrow lines from the visible to nearꢀIR. Emission
spectra were recorded with = 394 nm. The main radiꢀ
( D0) 4f6 configuration, which
4
5d
x
Eu O , which has a loose spongelike structure.
2x 3
λ
ex
5
ation transitions in the range 550–720 nm from the D0
I
level to F2,
F1, and 7F0 levels belong to Eu local cenꢀ
7
7
3+
3
2
2
1
1
000
500
000
500
000
500
0
ters (Fig. 6). The line at 614 nm, which has the stronꢀ
5
7
gest emission, belongs to the D0
→
F2 transition.
5
7
Other transitions from the DJ excited levels to the FJ
ground levels are far less intense. In the shortꢀwaveꢀ
length spectral region, a peak appears at 594 nm
5
7
(
D0
strongest line of the D0
proves rather a high symmetry of the local surroundꢀ
→
F1) with an intensity commensurate to the
5
7
→
F2 transition, and this
3
+
ing of Eu ions in Sc1 – xEu (СH COO)3. The
absence of emission from the DJ (J = 1, 2, or 3)
x
3
5
excited levels is likely because of a high phonon
energy in the host, which results from rapid radiaꢀ
5
tionless relaxation to the D0 level. A comparison of
the emission spectra of Sc1 – xEu (СH COO) samꢀ
x
3
3
3
+
ples with different Eu contents shows that the samꢀ
ple of composition Sc Eu (СH COO) has the most
0.9
0.1
3
3
560
600
640
680
720
, nm
pronounced luminescence.
λ
In summary, our study resulted in the development and
implementation of methods for preparing europiumꢀ
doped scandium sesquioxide in two morphological types.
Using thermolysis of Sc1 – xEu (СH COO)3, we prepared
Fig. 7. Cathodoluminescence spectrum of Sc1.95Eu0.05O3
prepared by thermolysis of Sc0.975Eu0.025(СH COO)3.
x
3
3
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 57 No. 12 2012

1534
BAKLANOVA et al.
The nanosized condition of the Sc2 – 2xEu O samples
6. V. Lupei, A. Lupei, G. Boulon, et al., J. Alloys Compd.
51, 179 (2008).
7. V. Lupei, A. Lupei, C. Gheorghe, and A. Ikesue,
J. Lumin. 128, 901 (2008).
8. V. Lupei, A. Lupei, C. Gheorghe, and A. Ikesue,
J. Lumin. 128, 918 (2008).
9. A. C. Bravo, L. Longuet, D. Autissier, et al., Opt.
2x
3
4
was verified by SEM and Scherrer estimations of parꢀ
ticle sizes. Inasmuch as mixtures of scandium and
europium nitrates with ethylene glycol represent a
homogeneous liquid mass (gel), they can be used to
prepare Sc2 – 2xEu O supported on some porous supꢀ
2x
3
port, for example, on silica, by impregnating the supꢀ
port followed by heat treatment of the supported sesquiꢀ
Mater. 31, 734 (2009).
oxide. Nanoparticle sizes in Sc2 – 2xEu O powders preꢀ 10. V. Lupei, A. Lupei, C. Gheorghe, et al., Opt. Mater. 31
,
,
,
2x
3
pared by reaction (1) are less than 12.3 nm, which
renders them attractive for manufacturing highꢀdensity 11. H. Kuhn, M. Fechner, A. Kahn, et al., Opt. Mater. 31
ceramics. The luminescence spectra of Sc2 – 2xEu O
1636 (2009).
samples are identical, regardless of whether the samꢀ 12. V. Lupei, A. Lupei, C. Gheorghe, et al., J. Lumin. 129
ples were prepared from ultrafine powders or from pelꢀ
1862 (2009).
lets manufactured by cold compaction. Having a 13. I. Trabelsi, R. Aaalej, M. Dammak, et al., J. Lumin.
unique set of physical properties and fairly high radiaꢀ
130, 927 (2010).
tion and chemical stability, europiumꢀdoped scanꢀ 14. M. Galseran, M. C. Pujol, J. J. Carvajal, et al.,
dium sesquioxide is, undoubtedly, a promising lumiꢀ
J. Lumin. 130, 1437 (2010).
734 (2009).
2x
3
nophore material active in the visible spectral region 15. S. P. Feofilov, D. V. Arsentyev, and A. B. Kulinkin,
and available due to the preparation methods develꢀ
oped in this study.
J. Lumin. 130, 438 (2011).
16. R. M. Krsmanovic, Z. Antic, M. G. Nikolic, et al.,
Ceram. Int. 37, 525 (2011).
1
7. C. Feldmann and J. Merikhi, J. Mater. Sci. 38, 1731
2003).
ACKNOWLEDGMENTS
(
1
8. V. N. Krasil’nikov, O. I. Gyrdasova, A. P. Tyutyunnik,
We are grateful to O.A. Kaigorodova and
E.G. Vovkotrub for their technical assistance in carryꢀ
ing out spectral analyses.
et al., Proceedings of the 12th International Symposium
“
Order, Disorder, and Properties of Oxides” (pos. Loo,
RostovꢀonꢀDon), Vol. 1, p. 288 [in Russian].
This study was supported by the Russian Foundaꢀ
tion for Basic Research (project no. 12ꢀ03ꢀ00453ꢀa)
and the Presidium of the Russian Academy of Sciꢀ
ences (project nos. 12ꢀTꢀ3ꢀ1008 and 12ꢀUꢀ3ꢀ1009).
1
2
9. W. Chen, F. Li, and J. Yu, Mater. Lett. 60, 57 (2006).
0. X.ꢀJ. Liu, H.ꢀL. Li, R.ꢀJ. Xie, et al., J. Lumin. 127, 469
(2007).
2
1. A. A. Korneva, V. N. Krasil’nikov, S. N. Shkerin, et al.,
RU Patent No. 2387052 (2010).
2
2. V. N. Krasil’nikov, O. I. Gyrdasova, S. N. Shkerin,
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RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 57 No. 12 2012