Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-19T06:02:27.027Z Has data issue: false hasContentIssue false
  • English
  • Français

Semiconducting CsMo4−x O12(x≍0.13): Room temperature crystal structure and resistivity anisotropy of a new alkali molybdenum bronze

Published online by Cambridge University Press:  31 January 2011

S. C. Abrahams ,
P. Marsh ,
L. F. Schneemeyer ,
C. E. Rice  and
S. E. Spengler
S. C. Abrahams
Affiliation:
AT&T Bell Laboratories, Murray Hill, New Jersey 07974
P. Marsh
Affiliation:
AT&T Bell Laboratories, Murray Hill, New Jersey 07974
L. F. Schneemeyer
Affiliation:
AT&T Bell Laboratories, Murray Hill, New Jersey 07974
C. E. Rice
Affiliation:
AT&T Bell Laboratories, Murray Hill, New Jersey 07974
S. E. Spengler
Affiliation:
AT&T Bell Laboratories, Murray Hill, New Jersey 07974
Get access

Abstract

Cesium molybdenum bronze, CsMo4xO12, is a recently discovered highly anisotropic semiconductor that crystallizes in the monoclinic system with space group C2/m and four formulas in the unit cell. The lattice constants at 295 K are a = 19.063(5), b = 5.5827(23), c = 12.1147(23) Å, and β = 118.94(2)°. The integrated intensities of 13.529 reflections within a full sphere of reciprocal space with radius (sin θ)/λ≤0.75 Å−1 were measured on a CAD-4 diffractometer with MoKα radiation, resulting in 12 553 reflections above background. Correction and averaging in C2/m gave 1923 significant and independent structure factors, for an internal unweighted agreement factor of 0.0288. The crystal structure was solved from the Patterson function and Fourier series and refined by the method of least squares. The Cs atoms occupy two different sites; both, as well as the nine independent O atom sites, are fully occupied, but the four independent Mo atom sites contain significant Schottky defects, with x = 0.132(8) in the chemical formula. All metal atoms undergo significant anharmonic motion. The final agreement factor R = 0.0269, Two Mo atoms are tetrahedrally, the other two octahedrally, coordinated. The average tetrahedral Mo–O distance is 1.761 Å, the octahedral distance is 1.950 Å. Bond length–bond strength considerations suggest that Mo6+ ions (almost) completely occupy the tetrahedral sites whereas the octahedral sites are (almost) half occupied by Mo6+, half by Mo5+ ions, resulting in charge balance. Infinite polyhedral sheets of corner-sharing Mo–O octahedra and tetrahedra form normal to the a axis, separated by linear arrays of Cs+ ions. The resistivity in this and other low-dimensional alkali molybdenum bronzes is a minimum (10−1–10−2 Ω cm) in the direction along which both corner-sharing octahedra, and the shortest contacts between cations arranged in infinite chains, form. The resistivity normal to the polyhedral sheets is about 2 orders of magnitude greater, at ∼ 10 Ω cm.

Type
Articles
Information
Journal of Materials Research , Volume 2 , Issue 1 , February 1987 , pp. 82 - 90
Copyright
Copyright © Materials Research Society 1987

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Dumas, J., Schlenker, C., Marcus, J., and Buder, R., Phys. Rev. Lett. 50, 757 (1983).CrossRefGoogle Scholar
2Fleming, R. M., Synth. Met. 13, 241 (1986).CrossRefGoogle Scholar
3Schlenker, C., Dumas, J., Escribe-Filippini, C., Guyot, H., Marcus, J., and Fourcaudot, G., Philos. Mag. B 52, 643 (1985).CrossRefGoogle Scholar
4Schneemeyer, L. F., DiSalvo, F. J., Fleming, R. M., and Waszczak, J. V., J. Solid. State Chem. 54, 358 (1984).CrossRefGoogle Scholar
5Greenblatt, M., McCarroll, W. C., Neifeld, R., Croft, M., and Waszczak, J. V., Solid. State Commun. 51, 671 (1984).CrossRefGoogle Scholar
6Brusetti, R., Chakraverty, B. K., Devenyi, J., Dumas, J., Marcus, J., and Schlenker, C., Recent Developments in Condensed Matter Phys-ics, edited by Devreese, J. T., Lemmens, L. F., Doren, V. E. Van, and Royen, J. Van (Plenum, New York, 1981), Vol. 2, p. 181.CrossRefGoogle Scholar
7Schneemeyer, L. F., Spengler, S. E., DiSalvo, F. J., Waszczak, J. V., and Rice, C. E., J. Solid State Chem. 55, 158 (1984).CrossRefGoogle Scholar
8Kelly, K. L. and Judd, D. B., Natl. Bur. Stand. (U.S.) Circ. 553 (1965) (including supplement, Standard Sample No. 2106).Google Scholar
9Enraf-Nonius CAD-4 Operation Manual, Delft, 1982 (unpublished).Google Scholar
10International Tablesfor X-ray Crystallography, edited by Ibers, J. A. and Hamilton, W. C. (Kynoch, Birmingham, 1974), Vol. IV.Google Scholar
11Abrahams, S. C. and Marsh, P., Acta Crystallogr. Sec. A (to be published).Google Scholar
12Weber, K., Acta Crystallogr. Sec. B 25, 1174 (1969).CrossRefGoogle Scholar
13Abrahams, S. C., Bernstein, J. L., and Keve, E. T., J. Appl. Crystal-logr. 4, 284 (1971).CrossRefGoogle Scholar
14Becker, P. J. and Coppens, P., Acta Crystallogr. Sec. A 30, 129 (1974); A 30, 148 (1974).Google Scholar
15See AIP Document No. PAPS JMREE-02–82–13 for 3 pages of an-harmonic thermal coefficients for the six independent metal atoms and 9 pages of measured and calculated structure factors of CsMo4_xO12. Order by PAPS number and journal reference from American Institute of Physics, Physics Auxiliary Publications Service, 335 East 45th Street, New York, NY 10017. The price is $1.50 for each microfiche (98 pages) or $5.00 for a photocopy. Airmail additional. Make checks payable to the American Institute of Physics.Google Scholar
16Error values here and later in this paper given in parentheses correspond to the least significant digits in the function value.Google Scholar
17Abrahams, S. C., J. Appl. Crystallogr. 5, 143 (1972).CrossRefGoogle Scholar
18Busing, W. R., Martin, K. O., and Levy, H. A., J. Appl. Crystallogr. 6, 309 (1973).Google Scholar
19Svensson, C., Abrahams, S. C., and Bernstein, J. L., J. Chem. Phys. 71, 5191 (1979).CrossRefGoogle Scholar
20Schröder, F. A., Acta Crystallogr. Sec. B 31, 2294 (1975).CrossRefGoogle Scholar
21Smith, G. W. and Ibers, J. A., Acta Crystallogr. 19, 269 (1965).CrossRefGoogle Scholar
22Young, A. P. and Schwartz, C. M., Science 141, 348 (1963).CrossRefGoogle Scholar
23Abrahams, S. C., J. Chem. Phys. 46, 2052 (1967).CrossRefGoogle Scholar
24Ghedira, M., Chenavas, J., Marezio, M., and Marcus, J., J. Solid State Chem. 57, 300 (1985).CrossRefGoogle Scholar
25Mumme, W. G. and Watts, J. A., J. Solid State Chem. 2, 16 (1970).CrossRefGoogle Scholar
26Shannon, R. D., Acta Crystallogr. Sec. A 32, 751 (1976).Google Scholar
27Graham, J. and Wadsley, A. D., Acta Crystallogr. 20, 93 (1966).CrossRefGoogle Scholar
28Stephenson, N. C. and Wadsley, A. D., Acta Crystallogr. 18, 241 (1965).CrossRefGoogle Scholar
29Bouchard, G. H., Perlstein, J., and Sienko, M. J., Inorg. Chem. 6, 1682 (1967).CrossRefGoogle Scholar
30Ganne, M., Boumaza, A., Dion, M., and Dumas, J., Mater. Res. Bull. 20, 1297 (1985).CrossRefGoogle Scholar
31Vincent, H., Ghedira, M., Marcus, J., Mercier, J., and Schlenker, C., J. Solid State Chem. 47, 113 (1983).CrossRefGoogle Scholar
32Schultz, A. J., Horiuchi, H., and Krause, H. B., Acta Crystallogr. Sec. C 42, 641 (1986).CrossRefGoogle Scholar
33Wold, A., Kunnmann, W., Arnott, R. J., and Ferretti, A., Inorg. Chem. 3, 545 (1964).CrossRefGoogle Scholar
34Pouget, J. P., Kagoshima, S., Schlenker, C., and Marcus, J., J. Phys. Lett.4, L–113 (1983).Google Scholar
35Zachariasen, W. H., J. Less-Common Metals 62, 1 (1978).CrossRefGoogle Scholar
36Barrett, C. S., Acta Crystallogr. 9, 971 (1956).CrossRefGoogle Scholar
37Meyerhoffand, K., Uhgelenk, J., Acta Crystallogr. 12, 32 (1959).CrossRefGoogle Scholar
38Buder, R., Devenyi, J., Dumas, J., Marcus, J., Mercier, J., Schlenker, C., and Vincent, H., J. Phys. Lett. 43, L–59 (1982).CrossRefGoogle Scholar
39Whangbo, M. H. and Schneemeyer, L. F., Inorg. Chem. 25, 2424 (1986).CrossRefGoogle Scholar