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A new strontium molybdate: SrMo5O8
Journal of Alloys and Compounds, 190 (1992) L19-L21 J A L C O M 456
L19
Letter
A new strontium molybdate: SrMosO8
We report here the experimental details on the existence of a new strontium molybdate, SrMos08 (J@
R. Andruszkiewicz and M. Wotcyrz
^
/
Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 937, 50-950 Wroctaw (Poland)
,'/
/
\ \
\
Mo~
(Received August 1, 1992)
\ \ \\
\ \ Sr Fig. 1. The localization of the J-SrMosO8 in the diagram of MoSr-O system. M0
There is some evidence in the literature [1-4] on the existence of strontium molybdates with molybdenum valency equal to four, five and sex, namely, the black-brownish Sr2Mo(/V)O4, SrMo(/V)O3 of perovskite structure (the product of the SrMo(V)206dismutation), the tetragonal SrMo(V/)O4,SraMo(V/)O6of perovskite structure and the SrMo(VD3Olo-nH20 (where n = 1.75, 3, 4) prepared in water.
DHH Powder
Di F~'rso~: Ion
phase), with average molybdenum valency equal to 2.8. This compound was prepared from high purity SrMoO4 (synthesized according to the procedure described in ref. 5), MoO2 [6] and powdered molybdenum. The substrates in an appropriate chemical composition were
$,ys~em
3eO0-
2700
n g
)I--
-
1800-
IO0
-
o
(b)
Z
Ul I-
Z
I 0. O0
20.
O0
30.
O0
40.
O0
gO. O0
SO. O0
70 • O0
20
t"
]
Fig. 2. X-ray powder diffraction diagram of the J-SrMosO~; (a) experimental data; (b) stick diagram representing indexed pattern from Table 1.
0925-8388/92/$5.00
© 1 9 9 2 - Elsevier Sequoia. All fights reserved
Letter
L20 T
A
B
L
E
1.
X-ray diffraction pattern of J-SrMosO8
h
k
l
2Oobs
2(gcalc
A2(9
dob~
1/lo
1 1 2 0 0 - 1 0 - 2 1 2 - 3 3 1 -3 - 1 2 - 3 1 4 2 - 3 - 1 - 4 - 2 - 4 0 3 1 - 2 1 -3 3 4 - 1 - 4 - 2 1 4 4 1 5 1 - 4 2 6 3 - 2 6 - 5 - 4 1
1 1 0 2 2 2 0 0 2 2 1 1 3 0 3 2 2 2 0 0 2 1 1 1 0 4 1 2 2 1 2 1 1 3 3 3 0 2 3 4 2 5 4 4 0 2 5 0 3 2 6
0 1 1 0 1 1 2 2 1 0 1 0 0 2 1 1 1 2 1 2 2 3 1 3 2 0 3 3 3 3 3 2 1 3 1 3 4 3 0 2 1 0 1 2 3 3 3 1 4 5 2
13.48 16.08 18.85 19.36 23.06 23.31 24.93 25.87 26.49 27.16 28.74 30.11 30.77 31.14 32.05 32.54 33.45 35.56 36.04 36.23 36.92 37.07 37.39 37.57 38.25 39.32 40.49 40.95 41.39 43.26 44.12 45.41 45.50 46.77 47.06 47.19 48.65 48.75 48.87 49.94 50.01 50.73 54.37 54.53 58.86 59.42 63.05 64.94 66.56 67.68 68.82
13.48 16.09 18.86 19.36 23.05 23.31 24.92 25.86 26.48 27.16 28.75 30.11 30.76 31.13 32.04 32.52 33.46 35.55 36.04 36.23 36.92 37.07 37.40 37.57 38.25 39.31 40.49 40.93 41.39 43.28 44.11 45.41 45.47 46.78 47.06 47.20 48.64 48.78 48.86 49.91 50.00 50.73 54.39 54.52 58.87 59.45 63.05 64.94 66.56 67.67 68.83
0.00 - 0.01 - 0.01 0.00 0.01 0.00 0.01 0.01 0.01 0.00 - 0.01 0.00 0.01 0.01 0.01 0.02 - 0.01 0.01 0.00 0.00 0.00 0.00 - 0.01 0.00 0.00 0.01 0.00 0.02 0.00 - 0.02 0.01 0.00 0.03 - 0.01 0.00 - 0.01 0.01 - 0.03 0.01 0.03 0.01 0.00 - 0.02 0.01 - 0.01 - 0.03 0.00 0.00 0.00 0.01 - 0.01
6.5623 5.5058 4.7051 4.5816 3.8542 3.8127 3.5691 3.4411 3.3617 3.2808 3.1033 2.9653 2.9038 2.8700 2.7900 2.7490 2.6768 2.5225 2.4902 2.4777 2.4326 2.4230 2.4033 2.3921 2.3513 2.2896 2.2260 2.2023 2.1797 2.0899 2.0511 1.9956 1.9918 1.9406 1.9293 1.9244 1.8701 1.8664 1.8620 1.8248 1.8223 1.7981 1.6859 1.6815 1.5675 1.5541 1.4732 1.4349 1.4037 1.3833 1.3630
100 15 11 11 8 10 7 11 7 6 33 21 78 23 12 9 38 30 17 23 7 9 26 53 6 20 15 26 21 15 18 9 9 20 46 81 12 18 13 18 19 26 28 35 4 9 23 21 8 4 8
-
-
-
-
-
-
-
-
-
well g r o u n d , p r e s s e d into p e l l e t s a n d h o m o g e n i z e d in
an excess of oxygen the J-phase undergoes an oxidation
e v a c u a t e d q u a r t z a m p o u l e s a t 1373 K f o r o n e d a y . X-ray powder diffraction analysis of the Sr-Mo-O
according to the equation:
samples belonging to the SrMoO4-MoO2-Mo triangle h a s r e v e a l e d t h a t a t 1373 K t h e J - p h a s e r e m a i n s i n e q u i l i b r i u m w i t h S r M o O 4 , M o O 2 a n d M o (Fig. 1). U n d e r
S r M o 5 0 8 + 4 0 2 = S r M o O 4 + 4MOO3. This fact was a m a i n o b s t a c l e to t h e e l a b o r a t i o n o f a simple method for single crystal growth.
Letter
Figure 2 shows the X~ray powder diffraction diagram of the J-phase collected on a Siemens D-5000 diffractometer (Bragg-Brentano geometry, CuKa radiation). The sample was also measured with an internal standard (silicon) in order to improve the accuracy. The absolute error on the position of the peaks was estimated at less than 0.02 ° (20). This data was used in the indexing procedure (program ITO [7]) followed by a subsequent LSQ refinement of the lattice parameters. The results obtained were as follows: Crystallographic system: monoclinic; Bravais lattice: primitive; a=9.959(1) /~, b=9.160(1) /~, c=7.564(1) /~, /3 = 109.24(1) °, V= 651.446 ~3, Z = 4, M = 695.32, d~=7.09 g cm -3, dm=7.04(2) g cm -3, F(20)=47.7 (0.0076, 55). The experimental density d m was measured pycnometrically. M is a molecular weight and F(20), a SmithSnyder figure of merit [8]. the indexed pattern is presented in Table 1. The lattice parameters of SrMo508 show very large similarity to those of some molybdates of ferrous metals, i.e. FeMoO4, C o M o O 4 and NilV[oO 4. Therefore, we suppose that their crystal structures should also be similar. The structure of SrMo508 seems to be a densified modification of CoMoO4 [9] in which an additional eight molybdenum atoms fill the vacant positions in the distorted perovskite lattice of CoMoO4. Unfortu-
L21
nately, till now, we have not found any proper structural model. The J-phase with valence electron concentration equal to 5.71 [10] is not a superconductor down to the liquidhelium temperature.
Acknowledgments The authors express their thanks to Dr K. Rogacki for low temperature resistivity measurements.
References 1 R. Scholder and W. Klemm, Angew. Chem., 66 (1954) 461. 2 J. D. H. Donnay (ed.), ACA Monograph, Number 5: Crystal Data, Determinative Tables, American Crystallographic Association, Washington, 1963, p. 620. 3 I. N. Belyaev, L. I. Medvedeva, E. G. Fesenko and M. F. Kupriyanov, Neorg, Mater. (in Russian), 1 (1965) 924. 4 J. Meullemeestre, Bull. Soc. Chim. France, (1978), 1-236. 5 G. Tamman and C. Westerhold, Z. anorg, allg. Chem., 149 (1925) 35. 6 L. L. Y. Chang and B. Phillips, J. Am. Ceram. Soc., 52 (1969) 527. 7 J. W. Visser, J. Appl. Crystallogr., 2 (1969) 89. 8 G. S. Smith and R. L. Snyder, J. Appl. Crystallogr., 12 (1979) 60. 9 G. W. Smith and J. A. lbers, Acta Crystallogr., 19 (1965) 269. 10 K. Yvon, in G. K. Shenoy, B. D. Dunlap and F. Y. Fradin (eds.), Ternary Superconductors, Elsevier, Amsterdam, 1981, p. 15.
L19
Letter
A new strontium molybdate: SrMosO8
We report here the experimental details on the existence of a new strontium molybdate, SrMos08 (J@
R. Andruszkiewicz and M. Wotcyrz
^
/
Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 937, 50-950 Wroctaw (Poland)
,'/
/
\ \
\
Mo~
(Received August 1, 1992)
\ \ \\
\ \ Sr Fig. 1. The localization of the J-SrMosO8 in the diagram of MoSr-O system. M0
There is some evidence in the literature [1-4] on the existence of strontium molybdates with molybdenum valency equal to four, five and sex, namely, the black-brownish Sr2Mo(/V)O4, SrMo(/V)O3 of perovskite structure (the product of the SrMo(V)206dismutation), the tetragonal SrMo(V/)O4,SraMo(V/)O6of perovskite structure and the SrMo(VD3Olo-nH20 (where n = 1.75, 3, 4) prepared in water.
DHH Powder
Di F~'rso~: Ion
phase), with average molybdenum valency equal to 2.8. This compound was prepared from high purity SrMoO4 (synthesized according to the procedure described in ref. 5), MoO2 [6] and powdered molybdenum. The substrates in an appropriate chemical composition were
$,ys~em
3eO0-
2700
n g
)I--
-
1800-
IO0
-
o
(b)
Z
Ul I-
Z
I 0. O0
20.
O0
30.
O0
40.
O0
gO. O0
SO. O0
70 • O0
20
t"
]
Fig. 2. X-ray powder diffraction diagram of the J-SrMosO~; (a) experimental data; (b) stick diagram representing indexed pattern from Table 1.
0925-8388/92/$5.00
© 1 9 9 2 - Elsevier Sequoia. All fights reserved
Letter
L20 T
A
B
L
E
1.
X-ray diffraction pattern of J-SrMosO8
h
k
l
2Oobs
2(gcalc
A2(9
dob~
1/lo
1 1 2 0 0 - 1 0 - 2 1 2 - 3 3 1 -3 - 1 2 - 3 1 4 2 - 3 - 1 - 4 - 2 - 4 0 3 1 - 2 1 -3 3 4 - 1 - 4 - 2 1 4 4 1 5 1 - 4 2 6 3 - 2 6 - 5 - 4 1
1 1 0 2 2 2 0 0 2 2 1 1 3 0 3 2 2 2 0 0 2 1 1 1 0 4 1 2 2 1 2 1 1 3 3 3 0 2 3 4 2 5 4 4 0 2 5 0 3 2 6
0 1 1 0 1 1 2 2 1 0 1 0 0 2 1 1 1 2 1 2 2 3 1 3 2 0 3 3 3 3 3 2 1 3 1 3 4 3 0 2 1 0 1 2 3 3 3 1 4 5 2
13.48 16.08 18.85 19.36 23.06 23.31 24.93 25.87 26.49 27.16 28.74 30.11 30.77 31.14 32.05 32.54 33.45 35.56 36.04 36.23 36.92 37.07 37.39 37.57 38.25 39.32 40.49 40.95 41.39 43.26 44.12 45.41 45.50 46.77 47.06 47.19 48.65 48.75 48.87 49.94 50.01 50.73 54.37 54.53 58.86 59.42 63.05 64.94 66.56 67.68 68.82
13.48 16.09 18.86 19.36 23.05 23.31 24.92 25.86 26.48 27.16 28.75 30.11 30.76 31.13 32.04 32.52 33.46 35.55 36.04 36.23 36.92 37.07 37.40 37.57 38.25 39.31 40.49 40.93 41.39 43.28 44.11 45.41 45.47 46.78 47.06 47.20 48.64 48.78 48.86 49.91 50.00 50.73 54.39 54.52 58.87 59.45 63.05 64.94 66.56 67.67 68.83
0.00 - 0.01 - 0.01 0.00 0.01 0.00 0.01 0.01 0.01 0.00 - 0.01 0.00 0.01 0.01 0.01 0.02 - 0.01 0.01 0.00 0.00 0.00 0.00 - 0.01 0.00 0.00 0.01 0.00 0.02 0.00 - 0.02 0.01 0.00 0.03 - 0.01 0.00 - 0.01 0.01 - 0.03 0.01 0.03 0.01 0.00 - 0.02 0.01 - 0.01 - 0.03 0.00 0.00 0.00 0.01 - 0.01
6.5623 5.5058 4.7051 4.5816 3.8542 3.8127 3.5691 3.4411 3.3617 3.2808 3.1033 2.9653 2.9038 2.8700 2.7900 2.7490 2.6768 2.5225 2.4902 2.4777 2.4326 2.4230 2.4033 2.3921 2.3513 2.2896 2.2260 2.2023 2.1797 2.0899 2.0511 1.9956 1.9918 1.9406 1.9293 1.9244 1.8701 1.8664 1.8620 1.8248 1.8223 1.7981 1.6859 1.6815 1.5675 1.5541 1.4732 1.4349 1.4037 1.3833 1.3630
100 15 11 11 8 10 7 11 7 6 33 21 78 23 12 9 38 30 17 23 7 9 26 53 6 20 15 26 21 15 18 9 9 20 46 81 12 18 13 18 19 26 28 35 4 9 23 21 8 4 8
-
-
-
-
-
-
-
-
-
well g r o u n d , p r e s s e d into p e l l e t s a n d h o m o g e n i z e d in
an excess of oxygen the J-phase undergoes an oxidation
e v a c u a t e d q u a r t z a m p o u l e s a t 1373 K f o r o n e d a y . X-ray powder diffraction analysis of the Sr-Mo-O
according to the equation:
samples belonging to the SrMoO4-MoO2-Mo triangle h a s r e v e a l e d t h a t a t 1373 K t h e J - p h a s e r e m a i n s i n e q u i l i b r i u m w i t h S r M o O 4 , M o O 2 a n d M o (Fig. 1). U n d e r
S r M o 5 0 8 + 4 0 2 = S r M o O 4 + 4MOO3. This fact was a m a i n o b s t a c l e to t h e e l a b o r a t i o n o f a simple method for single crystal growth.
Letter
Figure 2 shows the X~ray powder diffraction diagram of the J-phase collected on a Siemens D-5000 diffractometer (Bragg-Brentano geometry, CuKa radiation). The sample was also measured with an internal standard (silicon) in order to improve the accuracy. The absolute error on the position of the peaks was estimated at less than 0.02 ° (20). This data was used in the indexing procedure (program ITO [7]) followed by a subsequent LSQ refinement of the lattice parameters. The results obtained were as follows: Crystallographic system: monoclinic; Bravais lattice: primitive; a=9.959(1) /~, b=9.160(1) /~, c=7.564(1) /~, /3 = 109.24(1) °, V= 651.446 ~3, Z = 4, M = 695.32, d~=7.09 g cm -3, dm=7.04(2) g cm -3, F(20)=47.7 (0.0076, 55). The experimental density d m was measured pycnometrically. M is a molecular weight and F(20), a SmithSnyder figure of merit [8]. the indexed pattern is presented in Table 1. The lattice parameters of SrMo508 show very large similarity to those of some molybdates of ferrous metals, i.e. FeMoO4, C o M o O 4 and NilV[oO 4. Therefore, we suppose that their crystal structures should also be similar. The structure of SrMo508 seems to be a densified modification of CoMoO4 [9] in which an additional eight molybdenum atoms fill the vacant positions in the distorted perovskite lattice of CoMoO4. Unfortu-
L21
nately, till now, we have not found any proper structural model. The J-phase with valence electron concentration equal to 5.71 [10] is not a superconductor down to the liquidhelium temperature.
Acknowledgments The authors express their thanks to Dr K. Rogacki for low temperature resistivity measurements.
References 1 R. Scholder and W. Klemm, Angew. Chem., 66 (1954) 461. 2 J. D. H. Donnay (ed.), ACA Monograph, Number 5: Crystal Data, Determinative Tables, American Crystallographic Association, Washington, 1963, p. 620. 3 I. N. Belyaev, L. I. Medvedeva, E. G. Fesenko and M. F. Kupriyanov, Neorg, Mater. (in Russian), 1 (1965) 924. 4 J. Meullemeestre, Bull. Soc. Chim. France, (1978), 1-236. 5 G. Tamman and C. Westerhold, Z. anorg, allg. Chem., 149 (1925) 35. 6 L. L. Y. Chang and B. Phillips, J. Am. Ceram. Soc., 52 (1969) 527. 7 J. W. Visser, J. Appl. Crystallogr., 2 (1969) 89. 8 G. S. Smith and R. L. Snyder, J. Appl. Crystallogr., 12 (1979) 60. 9 G. W. Smith and J. A. lbers, Acta Crystallogr., 19 (1965) 269. 10 K. Yvon, in G. K. Shenoy, B. D. Dunlap and F. Y. Fradin (eds.), Ternary Superconductors, Elsevier, Amsterdam, 1981, p. 15.