Low-temperature process of the cubic lanthanide sesquisulfides:remarkable stabilization of the γ-Ce₂S₃ phasei

Abstract

Upon treating the corresponding oxalates with carbon disulfide (p_CS2=130 Torr) at a heating rate of 5 °C min^-1 , it is shown that the cubic γ-phase of pure rare-earth sesquisulfides (γ-Ln₂S₃) can be obtained at 800 °C from samarium to holmium (also yttrium) and at 1000 °C from neodymium to dysprosium. By working on ternary sulfides Ce_2-xLn_xS₃ , it has been shown that the stabilization of the γ-phase occurs when the average ionic radius ranges between 1.015 and 1.104 Å at 800 °C. However, the nature of the observed sulfide phase also depends greatly on the experimental conditions, i.e. the nature of the precursor and the heating rate. At 800 °C and 5 °C min^-1 , cerium oxalate leads to the β-phase while cerium nitrate leads to the α-phase. On the other hand, with cerium oxalate, the lower the heating rate the higher the amount of cubic γ-phase obtained.

References

1. Rhône-Poulenc, Fr. Pat., 85 06546, 1985.
2. G. Velleret and J. M. Tourre, Proceedings of ANTEC93, New Orleans, Society of Plastics Engineering, 1993.
3. P. Maestro and H. Huguenin, J. Alloys Compd., 1995, 225, 520.
4. R. Mauricot, P. Gressier, M. Evain and R. Brec, J. Alloys Compd., 1995, 223, 130.
5. J. Flahaut, in Handbook on the Physics and Chemistry of Rare-Earths, ed. K. A. Gschneider Jr. and L. Eyring, North-Holland, Amsterdam, 1979, vol. 4, p. 1, and references therein.
6. M. Guittard and J. Flahaut, in Synthesis of Lanthanide and Actinide Compounds, ed. G. Meyer and L. R. Morss, Kluwer Academic, Dordrecht, 1991, p. 321, and references therein.
7. C. T. Prewitt and A. W. Sleight, Inorg. Chem., 1968, 7, 1090.
8. P. Besancon and P. Laruelle, C.R. Acad. Sci. Paris, Ser. C, 1969, 268, 48.
9. P. Besancon, J. Solid State Chem., 1973, 7, 232.
10. D. Carre, P. Laruelle and P. Besancon, C.R. Acad. Sci. Paris, Ser. C, 1970, 270, 537.
11. T. Schleid and F. Lissner, J. Less-Common Met., 1991, 175, 309.
12. W. H. Zachariasen, Acta Crystallogr., 1949, 2, 57.
13. N. L. Eatough, A. W. Webb and H. T. Hall, Inorg. Chem., 1969, 8, 2069.
14. K. J. Range, K. G. Lange and H. Drexler, Comments Inorg. Chem., 1984, 3, 171.
15. S. H. Han, K. A. Gschneidner Jr. and B. J. Beaudry, J. Alloys Compd., 1992, 181, 463.
16. G. Sallavuard and R. A. Pâris, C.R. Acad. Sci. Paris, Ser. C, 1970, 271, 1460.
17. P. Kumta and S. Risbud, Mater. Sci. Eng., B, 1989, 2, 281.
18. P. Pascal, in Nouveau Traité de Chimie Minérale, ed. Masson et C^ie, 1959, p. 1003.
19. S. A. Gallagher and W. R. Dworzak, J. Am. Ceram. Soc., 1985, 68, C206.
20. F. Marrot, PhD Thesis, Toulouse, 1994.
21. F. Marrot, A. Mosset, J. C. Trombe, P. Macaudiére and P. Maestro, J. Alloys Compd., in press.
22. S. Romero, A. Mosset and J. C. Trombe, personal communication, 1996.
23. J. R. Henderson, M. Muramoto, E. Loh and J. B. Gruber, J. Chem. Phys., 1967, 47, 3347.
24. M. Skrobian, N. Sato and T. Fujino, Thermochim. Acta, 1995, 249, 211.
25. W. Ollendorf and F. Weigel, Inorg. Nucl. Chem. Lett., 1969, 5, 263.
26. E. Hansson, Acta Chem. Scand., 1973, 27, 823.
27. K. G. Nair, V. V. Sreerajan and V. S. V. Nayar, Thermochim. Acta, 1980, 39, 253.
28. K. J. Range and R. Leeb, Z. Naturforsch., Teil B, 1976, 31, 311.
29. D. Carré, J. Flahaut, P. Khodadad, P. Laruelle, N. Rodier and V. Tien, J. Solid State Chem., 1973, 7, 321.
30. C. M. Fang, A. Meetsma, G. A. Wiegers and G. Boom, J. Alloys Compd., 1993, 201, 255.
31. M. Picon, L. Domange, J. Flahaut, M. Guittard and M. Patrie, Bull. Soc. Chim. Fr., 1960, 221.
32. R. D. Shannon, Acta Crystallogr., Sect. A, 1976, 32, 751.
33. A. Meetsma, A. Wiegers, R. J. Haange and J. L. de Boer, Acta Crystallogr., Sect. C, 1991, 47, 2287.
34. N. Rodier and V. Tien, C. R. Acad. Sci. Paris, Ser. C, 1977, 285, 133.
35. M. Cutler, R. L. Fitzpatrick and J. F. Leavy, J. Phys. Chem. Solids, 1963, 24, 319.
36. R. L. Fitzpatrick and Z. A. Munir, Mater. Res. Bull., 1967, 2, 939.
37. K. Vostrikova, S. Roméro, A. Mosset and J. C. Trombe, in preparation.
38. V. Tien and P. Khodadad, Bull. Soc. Chim. Fr., 1969, 1, 30.