Synthesis of substitutional solid solutions in Na2O-P 2O5-In2O3- MI 2I IO3 (MIII = Cr, Fe, and Mn) systems

Article abstract of DOI:10.1134/S0036023612050099

Solid solutions based on Na₇(InP₂O₇) ₄PO₄ and Na₃In₂(PO₄) ₃, where chromium, iron, and manganese substitute for indium, have been prepared. When chromium and iron substitute for indium in Na ₇(InP₂O₇)₄PO₄, a continuous solid solution series exists. When manganese substitutes for indium, it enters the compound in the oxidation state +3. The substitution of chromium for indium in Na₃In₂(PO₄)₃ occurs within the range from 0.11 to 0.74 (mol/mol), and that of iron for indium, from 0.09 to 0.62 (mol/mol). When manganese substitutes for indium, it enters the structure of the crystalline phase in insignificant amounts as a two-charged cation.

Full text of DOI:10.1134/S0036023612050099

ISSN 0036ꢀ0236, Russian Journal of Inorganic Chemistry, 2012, Vol. 57, No. 5, pp. 650–653. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © A.P. Ivanenko, P.G. Nagorny, R.S. Boiko, Z.I. Kornienko, 2012, published in Zhurnal Neorganicheskoi Khimii, 2012, Vol. 57, No. 5, pp. 718–721.
SYNTHESIS AND PROPERTIES
OF INORGANIC COMPOUNDS
Synthesis of Substitutional Solid Solutions in Na O–P O –In O –
2
2
5
2
3
III
III
M O (M = Cr, Fe, and Mn) Systems
A. P. Ivanenko , P. G. Nagorny , R. S. Boiko , and Z. I. Kornienko
2
3
a
b
b
b
a
Vernadsky Institute of General and Inorganic Chemistry, National Academy of Sciences of Ukraine, Kiev
b
Shevchenko National University, Ukraine
Received December 22, 2010
Abstract—Solid solutions based on Na (InP O ) PO and Na In (PO4)3, where chromium, iron, and manꢀ
7
2
7 4
4
3
2
ganese substitute for indium, have been prepared. When chromium and iron substitute for indium in
Na (InP O ) PO4, a continuous solid solution series exists. When manganese substitutes for indium, it enters
7
2 7 4
the compound in the oxidation state +3. The substitution of chromium for indium in Na In (PO ) occurs
3
2
4 3
within the range from 0.11 to 0.74 (mol/mol), and that of iron for indium, from 0.09 to 0.62 (mol/mol). When
manganese substitutes for indium, it enters the structure of the crystalline phase in insignificant amounts as
a twoꢀcharged cation.
DOI: 10.1134/S0036023612050099
Great interest has recently been paid to double crucibles were placed in a SShOLꢀ116 shaft furnace
phosphates due to their valuable physicochemical equipped with an RIFꢀ101 automated temperature
properties, such as pyroꢀ, piezoꢀ, ferroelectric, optiꢀ elevation and depression regulator. The molten soluꢀ
cal, and nonlinearꢀoptical properties [1–4]. One way tions obtained in this way were exposed at 1000–
to find materials with valuable properties is to study 1100
systems where solid solutions are formed.
plete homogeneity was reached. After this exposure, the
°
С for 2–6 h with intermittent stirring until comꢀ
I
2
melt was cooled at 50 K/min until crystallization started;
then, the cooling rate was decreased to 10–20 K/h. After
crystal formation was over, the melts were poured to a
copper sheet for rapid cooling. The crystalline phase
was washed off a remnant amorphous phase with dilute
solutions (5–10 wt %) of mineral acids (HCl, HNO3, or
The best studied double phosphates are M O
–
III
P O –M O systems, where MI = Li, Na, or K; MIII
Cr, Fe, Mn, In, etc. When indium(III) oxide reacts with
molten solutions of Na O–P O phosphate systems with
ratios of Na O : P O of 1.2–1.4 and 1.4–2.0 (mol/mol),
the reaction produces Na (InP O ) PO and H SO4). The solid phases prepared in this way were
=
2
5
2
3
2
2
5
2
2
5
7
2
7 4
4
2
Na In (PO4)3, respectively. It was of interest to study analyzed for tervalent metals and phosphorus.
3
2
whether solid solutions on their basis can be formed by
substituting chromium, iron, and manganese for
indium.
Phosphorus was determined as described in [5];
indium, chromium, and iron, by a rapid method as
described in [6]; and manganese as described in [7].
Xꢀray diffraction patterns were recorded for comꢀ
pounds and solid solutions on a DRONꢀ3.0 diffractoꢀ
EXPERIMENTAL
The materials used were sodium metaphosphate
NaPO3) prepared by calcination of sodium dihydroꢀ
meter (Cu
K radiation; 2 deg/min). Unit cell paramꢀ
α
(
eters were refined using INDEX software. IR spectra
were recorded as KBr disks on a URꢀ10 instrument in
phosphate (NaH PO (pure for analysis grade)) at
2
4
6
00
°
С; sodium pyrophosphate (Na P O7) prepared in
4 2
–1
the range 400–1600 cm . Electronic spectra were
the same way at 800
°
С; and indium(III) oxide (chemꢀ
recorded on a Specord Mꢀ40 doubleꢀbeam spectroꢀ
ically pure grade), chromium(III) oxide (chemically
pure grade), iron(III) oxide (chemically pure grade),
and manganese(III) oxide (pure grade).
Solid solutions were prepared by spontaneous crysꢀ
tallization from molten solutions of Na O–P O –
–1
photometer in the range
ν
= 30000–12000 cm .
Ionic conductivity was studied in selected samples on
an R5058 ac bridge at 1 mHz frequency using a universal
resistance box (Fig. 1); the tablet diameter was ~10 mm
and the thickness was 1–1.45 mm). Tabletꢀshaped
2
2
5
III
2
III
In O –M O (M = Fe, Cr, Mn) systems at temperꢀ samples were prepared as follows: a crystalline mateꢀ
2
3
3
atures in a range of 600–1100
Calculated amounts of the feed components were mortar and then dried at 50–60
pounded in an agate mortar to obtain a homogeneous was compacted into tablets under 100 atm and calꢀ
mass and then transferred to platinum crucibles; the cined at 900–1100
°
С.
rial was triturated with 5% vinyl alcohol in an agate
; the resulting blend
°
С
°
С.
650

SYNTHESIS OF SUBSTITUTIONAL SOLID SOLUTIONS
651
RESULTS AND DISCUSSION
3
III
In studying the Na O–P O –In O –M O system
2
2
5
2
3
2
3
(
Na O : P O = 1.2 (mol/mol); the tervalent metal oxide
2
2
2
5
ratio: 6–0.17 (wt/wt)), we prepared a solid solution series
III
of the general formula Na ([In xMx ]P O ) PO4. The
7
1 –
2
7 4
index
х varied within the following ranges: from 0.18 to
1
.00 for chromium, from 0.07 to 0.84 for iron, and
220 V
4
1
from 0.023 to 0.067 for manganese (Table 1).
Crystals were shaped as parallelograms and were
colored green when doped with chromium and blue
when doped with manganese. Ironꢀdoped crystals
were colorless.
5
The IR spectra of the compounds feature absorpꢀ
3
4
−
ν
tion bands of anionic groups: PO
( modes in the range
s
Fig. 1. Schematics of the apparatus used to study ionic
conductivity of solid solutions: ( ) furnace; ( ) V7ꢀ26 uniꢀ
versal voltmeter, ( ) microvoltmeter, ( ) PP thermocouꢀ
ple, and ( ) electrodes.
4
−
50–980 cm ) and P2O7 (a strong band at 745 cm–1
and and modes of the PO3 group at 1040, 1120,
130, 1150, and 1190 cm ) [8].
–
1
1
2
9
3
4
ν
s
ν
аs
5
–1
1
Electronic spectra helped us to establish that chroꢀ
For iron, the oxidation state +3 is verified by the folꢀ
mium, iron, and manganese in the crystals are in the
4
6
oxidation state +3. For chromium, the oxidation state lowing transitions:
T
→
А
(bands in the range
(bands in the range
1
1
А
3 is verified by the following transitions: T2g and 2Eg at 12000–13500 cm ), T2g
2
–1
4
6
→
+
1
1g
5000 cm–
1 4
,
T2g at 22 000 cm , and T1g at 32000 cm . 17500–18500 cm–1), 4А1g
–1
4
–1
,
and 4Eg (bands in the range
Table 1. Synthesis parameters for solid solutions based on sodium indium double orthophosphate and double phosphate
Initial ratio
Initial ratio
Reaction products
Tcr
, °C
III
Na O : P O (mol/mol)
2
2
5
In O : M2 O3 (wt/wt)
2
3
1
.2
Cr
6.00
Na (In0.82Cr0.18P O ) PO
750
810
880
900
740
725
725
660
745
715
755
720
740
770
770
680
865
735
810
840
7
2
7 4
4
4
4
2.50
1.33
0.17
Na (In0.52Cr0.48P O ) PO
7 2 7 4
Na (In0.42Cr0.58P O ) PO
7
2 7 4
Na (CrP O ) PO
4
7
2
7 4
Fe
6.00
Na (In0.93Fe0.07P O ) PO
7 2 7 4
4
4
4
4
2.50
1.33
0.17
Na (In0.88Fe0.12P O ) PO
7 2 7 4
Na (In0.80Fe0.20P O ) PO
7
2 7 4
Na (In0.16Fe0.84P O ) PO
7
2 7 4
Mn
Cr
6.00
.50
6.5
Na (In0.987Mn0.023P O ) PO
7 2 7 4
4
2
Na (In0.943Mn0.067P O ) PO
7 2 7 4
4
1
.4
Na In1.78Cr0.22(PO )
3
4 3
2
1
0
.75
Na In1.44Cr0.56(PO )
3
4 3
.5
.5
Na In1.16Cr0.84(PO )
3
4 3
Na In0.52Cr1.48(PO )
3
4 3
Fe
6.5
Na In1.82Fe0.18(PO )
3
4 3
2
1
0
.75
Na In1.72Fe0.28(PO )
3
4 3
.5
.5
Na In1.62Fe0.38(PO )
3
4 3
Na In0.76Fe1.24(PO )
3
4 3
Mn
6.5
.75
Na2.885In1.885Mn0.115(PO4)3
Na2.880In1.880Mn0.120(PO4)3
2
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 57 No. 5 2012

652
IVANENKO et al.
prepared solid solutions; the crystals were triclinic,
space group 21 (Table 2).
E
.2
3
2
2
2
1
1
0
0
4
P c
Fe
Ionic conductivity was studied for selected samples
Fig. 2). An abnormal conductivity versus temperature
dependence was observed in the range 300–475 С,
.8
.4
.0
.6
.2
.8
.4
(
Mn
°
which may serve as an indicator of secondꢀorder phase
transitions occurring within this temperature range
(
Fig. 3).
Cr
III
2
In studying the Na O–P O –In O –M O sysꢀ
2
2
5
2
3
3
tem with the ratio Na O : P O = 1.4 (mol/mol) and
2
2
5
the tervalent oxide ratio ranging from 6.5 to 0.5, we
prepared a solid solution series of the general formula
III
Na In2 – 2хM2x (PO ) . The index х varied from 0.11 to
3
4 3
0
.74 for chromium, from 0.09 to 0.62 for iron, and
1
0000 15000 20000 25000 30000 35000
ν
–1
, cm
from 0.115 to 0.12 for manganese; manganese enters
the solid solution structure as Mn2 (Table 1).
+
The compounds were prepared in plates; for solid
solutions where chromium substituted for indium, the
Fig. 2. Diffuse reflectance spectra of solid soltuions.
color changed from pink (Na In1.78Cr0.22(PO )
)
3
4 3
through grayꢀgreen (Na In1.16Cr0.84(PO ) ) to green
3
4 3
(
Na In0.52Cr1.48(PO4)3). We believe that the following
3
log
p
explanation is possible: from lowꢀchromium feeds,
compounds with high defect densities were formed
upon crystallization. Ironꢀdoped compounds crystalꢀ
lized into transparent crystals; manganeseꢀdoped
compounds, into white crystals.
2
1
3
1
1
0
9
8
7
6
1
In the IR spectra of solid solutions of the Na O–
2
III
P O –In O –M O system with the ratio Na O :
P2O5 = 1.4 (mol/mol), there are characteristic absorpꢀ
2
5
2
3
2
3
2
3
4
−
tion bands of
ν
аs(PO
)
at 1035, 1050, and 1070 cm–1
3
4
−
–1
and
ν
s(PO
)
at 980 and 930 cm . Doubly degenerate
–1
bending vibrations appear at 410 and 450 cm ; triply
degenerate asymmetric bending vibrations appear in
the range of 510–650 cm .
An inspection of the electronic diffuse reflectance
spectra shows that chromium and iron are in the oxiꢀ
dation state +3; the description of the spectra is similar
to that given above for the Na (InP O ) PO4ꢀbased
–1
1.2
1.4
1.6
10 /T, K
1.8
2.0
2.2
3
7
2
7 4
solid solutions. Manganese in the solid solutions is in
the oxidation state +2. This is supported by the nonapꢀ
pearance of absorption bands because of their low
intensities and an insignificant manganese concentraꢀ
tion.
III
Fig. 3. Ionic conductivity of Na ([In1 – Mx ]P O ) PO
4
7
x
2
7 4
compounds:
(
1
)
Na (In0.82Cr P O ) PO4,
(
2
)
)
7
0.18 2 7 4
Na (In0.80Fe P O ) PO4,
and
(3
7
0.20 2 7 4
Na (In0.987Mn0.023P O ) PO4.
7
2 7 4
The singleꢀphase constitution of these compounds
was verified by powder Xꢀray diffraction. This method
helped us to refine unit cell parameters of the prepared
solid solutions crystals and to establish that they
–
1
2
4000–24600 cm ); the absorption bands in the
–1
range 27000–33000 cm are chargeꢀtransfer bands.
For manganese, the oxidation state +3 is verified by
T2 transitions (bands in the range 16000–
0000 cm ). Transitions at higher energies (26000–
belong to orthorhombic space group
exception is Na In Fe (PO4)3, which crystallizes
R c. The only
3
5
5
Eg
→
g
3
0.76 1.24
–
1
2
3
(
in monoclinic crystal system. These data were used to
–1
0000 cm ) correspond to chargeꢀtransfer bands [9]
III
plot unit cell parameter versus tervalent metal (
M )
Fig. 2).
The singleꢀphase constitution of the compounds
was verified by powder Xꢀray diffraction. This techꢀ
concentration and to demonstrate that this plot obeys
Vegard’s rule (Table 2).
In summary, the formation of substitutional solid
III
nique was used to refine unit cell parameters of the solutions of compositions Na ([In1 – ]P O ) PO
M
7 x 2 7 4 4
x
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 57 No. 5 2012

SYNTHESIS OF SUBSTITUTIONAL SOLID SOLUTIONS
653
Table 2. Unit cell parameters of crystals of the solid soluꢀ for preparing the double phosphates of chromium and
tions prepared
iron, as well as by a small difference between the ionic
radii of chromium, iron, and indium. Manganese solid
solutions were formed with small ranges of х. This may
be explained by the nonꢀisostructureness of the correꢀ
sponding double phosphates of indium and mangaꢀ
nese, an increase in the manganese ionic radius, and
insignificant manganese(III) concentrations in molꢀ
ten solutions at the synthesis temperature.
Compound
a
, nm
b, nm
c
, nm
β, deg
Na (InP O ) PO space
1.4205
0.6613
7
2
7 4
4
group
P
4
21c
Na (In0.83Cr0.17P O ) PO
1.4205
1.4231
1.4191
1.4290
1.4219
1.4242
1.4226
0.6601
0.6172
0.6592
0.6607
0.6601
0.6618
6.6160
0.6598
0.6604
7
2
7 4
4
Na (In0.45Cr0.55P O ) PO
7
2
7 4
4
Na (CrP O ) PO
7
2
7 4
4
Na (In0.93Fe0.07P O ) PO
7
2
7 4
4
Na (In0.88Fe0.12P O ) PO
7
2
7 4
4
REFERENCES
Na (In0.80Fe0.20P O ) PO
7
2
7 4
4
Na (In0.16Fe P O ) PO
7
0.84
2
7 4
4
1. M. PintardꢀScrepel and F. d’Yvoire, J. Solid State
Chem. (1982).
Na (In0.987Mn0.023P2O ) PO 1.4244
7
7 4
4
Na (In0.943Mn
P O ) PO 1.4176
7
0.067
2 7 4 4
2. O. V. Gomenyuk, S. G. Nedilko, N. V. Stus, et al.,
Na In (PO ) space group
3
2
4 3
0.8207
2.1827
Funct. Mater. 11 (1), 153 (2004).
R
3
c
3
. M. PintardꢀScrepel, F. d’Yvoire, and F. Remy, C. R.
Acad. Sci. C 286, 381 (1978).
Na In1.78Cr0.22(PO )
Na In1.44Cr (PO )
Na In1.16Cr (PO )
Na In0.52Cr1.48(PO )
Na In1.82Fe0.18(PO )
Na In1.72Fe (PO )
Na In1.62Fe (PO )
Na In0.76Fe1.24(PO )
0.8175
0.8158
0.8190
0.8211
2.1817
2.2054
2.1826
2.1817
2.2054
2.1826
2.1957
2.1923
2.1976
2.1809
3
4 3
3
0.56
4 3
4. F. d’Yvoire, M. PintardꢀScrepel, and E. Beretey, C. R.
3
0.84
4 3
Acad. Sci. C 290 (10), 185 (1980).
3
4 3
5
. W. F. Hillebrand and G. E. Lundel, Applied Inorganic
Analysis with Special Reference to the Analysis of Metals,
Minerals, and Rocks (Wiley, New York, 1958; Khimiya,
Moscow, 1996).
3
4 3
3
0.28
4 3
3
0.38
4 3
2.1957 1.2758 0.6575 114.38
3
4 3
6. A. P. Ivanenko, P. G. Nagornyi, Z. I. Kornienko, et al.,
Na2.885In1.885Mn0.115(PO ) 0.8191
Na2.880In1.880Mn0.120(PO ) 0.8140
2.1843
2.1887
4 3
Zh. Anal. Khim. 62, 1293 (2007).
. A. K. Babko and A. T. Pilipenko, Colorimetric Analysis
4 3
7
(
Goskhimizdat, Moscow, 1951) [in Russian].
8. P. G. Nagornyi, Dokl. Natl. Akad. Nauk Ukr., No. 5,
41 (1998).
III
and Na In2 – 2хM2x (PO ) , where MIII = Fe or Cr, may
3
4 3
1
be explained by the isostructureness of the double
sodium indium phosphates that were used as the host
9
. A. Lever, Inorganic Electronic Spectroscopy (Elsevier,
Amsterdam, 1984; Mir, Moscow, 1987).
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 57 No. 5 2012