Abstract
The results obtained showed that the addition of small amounts of LiNO3 to the reacting mixed solids, consisting of equimolar proportion of Fe2O3 and basic MgCO3 much enhanced the thermal decomposition of magnesium carbonate. The addition of 12 mol% LiNO3 (6 mol% Li2O) decreased the decomposition temperature of MgCO3 from 525.5 to362°C. MgO underwent solid–solid interaction with Fe2O3 at temperatures starting from800°C yielding MgFe2O4. The amount of ferrite produced increased by increasing the precalcination temperature of the mixed solids. However, the completion of this reaction required prolonged heating at elevated temperature above 1100°C. Doping with Li2O much enhanced the solid–solid interaction between the mixed oxides leading to the formation of MgFe2O4 phase at temperatures starting from 700°C. The addition of 6 mol% Li2O to the mixed solids followed by precalcination at 1050°C for 4 h resulted in complete conversion of the reacting oxides into magnesium ferrite. The heat treatment of pure and doped solids at 900–1050°C effected the disappearance of most of IR transmission bands of the free oxides with subsequent appearance of new bands characteristic for MgFe2O4 structure. The promotion effect of Li2O towards the ferrite formation was attributed to an effective increase in the mobility of the various reacting cations. The activation energy of formation (ΔE) of magnesium ferrite was determined for pure and variously doped solids and the values obtained were 203, 126, 95 and 61 kJ mol−1 for pure mixed solids and those treated with 1.5, 3.0 and 6.0 mol% Li2O, respectively.
Similar content being viewed by others
References
G. A. Kolta, S. Z. El-Tawil, A. A. Ibrahim and N. S. Felix, Thermochim. Acta, 39 (1980) 359.
A. Feltz and H. Martin, Mater. Sci. Nonorg. React. Solids, 28 A (1985) 137.
R. K. Tami, K. K. Kamada and T. Ishci, React. Solids, 1 (1986) 309.
F. J. C. Toolenaar, J. Mater. Sci., 24 (1989) 1089.
G. A. El Shobaky, F. H. A. Abdalla and A. A. Fouad Zikry, Thermochim. Acta, 289 (1996) 81.
M. Crisan and D. Crisan, Mater. Sci. Monogr. (Ceram. Powder), (1983) 429.
G. A. El-Shobaky, A. A. Ibrahim and S. El-Defrawy, Thermochim. Acta, 131 (1988) 115.
G. A. El-Shobaky and A. A. Ibrahim, Thermochim. Acta, 132 (1988) 117.
G. A. El-Shobaky and A. A. Ibrahim, Bull. Soc. Chim. France, (1989) 34.
G. A. El-Shobaky, G. A. Fagal, A. Abd El-Aal and A. M. Ghozza, Thermochim. Acta, 256 (1995) 429.
G. A. El-Shobaky, F. H. A. Abdalla and A. M. Ghozza, Thermochim. Acta, 292 (1997) 123.
H. G. El-Shobaky, Thermochim. Acta, 343 (2000) 145.
O. E. Ayala, D. Lardizabal, A. Reyes, M. I. Rosales, J. A. Matutes and A. Gonzalez Arias, J. Therm. Anal. Cal., 59 (2000) 943.
T. Konvicka, P. Mosner and Z. Solc, J. Therm. Anal. Cal., 60 (2000) 629.
I. Rychlowska-Himmel and A. Blonska-Tabero, J. Therm. Anal. Cal., 56 (1999) 205.
V. Musat Bujoreanu and E. Segal, J. Therm. Anal. Cal., 61 (2000) 967.
V. Musat Bujoreanu and E. Segal, J. Thermal Anal., 50 (1997) 767.
H. Armendariz, G. Aguilar, P. Sales, M. Valenzuela, I. Schifter, H. Arriola and H. Nava, Appl. Catal., 92 (1992) 29.
T. Masahiron, A. Kazuhiri, N. Ken, M. Keisuke, Y. Takashi, T. Masamichi and T. Yutka, J. Mater. Sci., 28 (1993) 6753.
X. Peiuo, G. Xiongyi and D. Yingchum, J. East China Institute of Chemical Technology, 16 (1996) 706.
T. Mitev, T. Dimova and G. Khristova, Bulg. Sklar. Keram., 32 (1982) 207.
M. S. Selim, G. Turky, M. Shouman and G. A. El-Shobaky, Solid State Ionics, 120 (1999) 173.
G. Busca, E. Finocchio, V. Lorenzelli, M. Trombetta and S. A. Rossini, J. Chem. Soc. Faraday Trans., 92 (1996) 4687.
L. Dong, Z. Liu, Y. Hu, B. Xu and Y. Chen, J. Chem. Soc. Faraday Trans., 94 (1998) 3033.
N. J. Jebarathinam, M. Eswaramoorthy and V. Krishnasamy, Bull. Chem. Soc. Jpn., 67 (1994) 3334.
P. Lahiri and S. Sengupta, J. Chem. Soc. Faraday Trans., 91 (1995) 3489.
N. K. Singh, S. K. Tiwari, K. L. Anitha and R. N. Singh, J. Chem. Soc. Faraday Trans., 92 (1996) 2397.
J. Miki, M. Asanuma, Y. Tachibana and T. Shikada, J. Catal., 151 (1995) 323.
K. P. Tikhomolova, I. B. Dmitrieva and M. V. Ivanova, Russ. J. Appl. Chem., 71 (1998) 550.
G. R. Dube and V. S. Darshane, Bull. Chem. Soc. Jpn., 64 (1991) 2449.
Powder Diffraction File (JCPDS), International Centre for Diffraction Data, Swarthmore, PA 1979.
F. H. A. Abdalla, G. A. El-Shobaky and N. A. Hassan, J. Thermal Anal., 47 (1996) 1777.
F. A. Kroger, Chemistry of Imperfect Crystals, North-Holland, Amsterdam 1964.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
El-Shobaky, G.A., Radwan, N.R.E. & Radwan, F.M. Investigation of Solid-Solid Interactions between Pure and Li2O-Doped Magnesium and Ferric Oxides. Journal of Thermal Analysis and Calorimetry 68, 275–287 (2002). https://doi.org/10.1023/A:1014977820189
Issue Date:
DOI: https://doi.org/10.1023/A:1014977820189