The use of constant rate thermal analysis (CRTA) for controlling the texture of hematite obtained from the thermal decomposition of goethite

Abstract

Constant rate thermal analysis (CRTA) has been used for studying the decomposition of three synthetic needle-shaped goethite samples. This method controls the reaction temperature such that the reaction rate and partial pressure of water vapour are kept constant at a selected value. The effects of the pressure of water vapour generated during the dehydration of goethite and of the decomposition rate on the porosity of the resulting hematite have been studied. The effect of the particle size of the precursors on the texture of the final products has also been analysed. By this method, acicular particles of α-Fe₂O₃ with controlled porosity oriented along the c-lattice axis (the long axis of the particle) have been prepared.

References

1. H.-T. Sun, C. Cantalini, M. Faccio, M. Pelino, M. Catalano and L. Tapfer, J. Am. Ceram. Soc., 1996, 79, 927.
2. C. Cantalini and M. Pelino, J. Am. Ceram. Soc., 1992, 75, 546.
3. A. Brown, J. Hargreaves and B. Rijniersce, Catal. Lett., 1998, 53, 7.
4. H. Randall, R. Doepper and A. Renken, Ind. Eng. Chem. Res., 1997, 36, 2996.
5. R. M. Cornell and U. Schwertmann, The Iron Oxides. Structure, Properties, Reactions, Occurrence and Uses, VCH, Weinhein, 1996.
6. K. Raj and R. Moskovitz, J. Magn. Magn. Mater., 1990, 85, 233.
7. C. Sestier, D. Sabolovic, D. Geldwerth, M. Moumaris, J. Roger, J.-N. Pons and A. Halbreich, C. R. Acad. Sci., Ser. III, 1995, 318, 1141.
8. C. Sestier, M. F. Dasilva, D. Sabolovic, J. Roger and J. N. Pons, Electrophoresis, 1998, 19, 1220.
9. F. Gazoeau, J. C. Bacri, F. Gendron, R. Perzynsky, Y. L. Raikher, V. I. Stepanov and E. Dubois, J. Magn. Magn. Mater., 1998, 186, 157.
10. J. L. Dorman and D. Fiorani, Magnetic properties of fine particles, North Holland, Amsterdam, 1992.
11. M. P. Sharrok and R. E. Bodnar, J. Appl. Phys., 1985, 57, 3919.
12. Y. Maeda, E.C.L. Techn. Publ., 1978, 179, 1.
13. E. Herrero, M. V. Cabañas, V.-R. M., J. L. Martinez and J. M. Gonzalez-Calbet, Solid State Ionics, 1997, 101, 213.
14. M. Ozaki, S. Krathovil and E. Matijević, J. Colloid Interface Sci., 1984, 107, 199.
15. H. Naono and R. Fujiwara, J. Colloid Interface Sci., 1980, 73, 406.
16. H. Naono, K. Nakai, T. Sueyoshi and H. Yagi, J. Colloid Interface Sci., 1987, 120, 439.
17. M. Pelino, L. Toro, M. Petroni, A. Florindi and C. Cantalini, J. Mater. Sci., 1989, 24, 409.
18. P. F. Rossi, G. Caracciolo and G. Busca, Colloids Surf., 1988, 32, 75.
19. J. L. Rendon, J. Cornejo, P. De Arambarri and C. J. Serna, J. Colloid Interface Sci., 1983, 92, 508.
20. D. Beruto, Mater. Chem. Phys., 1983, 8, 233.
21. S. Hirokawa, T. Naito and T. Yamaguchi, J. Colloid Interface Sci., 1986, 112, 268.
22. P. Duvigneud and R. Derie, J. Solid State Chem., 1980, 34, 323.
23. C. Serna and J. Iglesias, J. Mater. Sci. Lett., 1986, 5, 901.
24. F. Watari, J. van Landuyrt, P. Delavignette, S. Amelickx and N. Igata, Phys. Status Solidi A, 1982, 73, 215.
25. G. Goss, Mineral. Mag., 1987, 51, 437.
26. E. Wolska and U. Schwertmann, Phys. Status Solidi A, 1989, 114, K11.
27. L. Volpe and M. Bougart, Catal. Rev. Sci. Eng., 1985, 27, 515.
28. G. W. van Oosterhout, Acta Crystallogr., 1960, 13, 932.
29. F. J. Gotor, M. Macías, A. Ortega and J. M. Criado, Int. J. Chem. Kinet., 1998, 30, 647.
30. A. M. Gadala and T. W. Livingston, Thermochim. Acta, 1989, 145, 1.
31. R. Derie, M. Ghodsi and C. Calvo-Roche, J. Therm. Anal., 1976, 9, 435.
32. U. Schwertmann, Thermochim. Acta, 1984, 78, 39.