Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-09T06:55:55.413Z Has data issue: false hasContentIssue false

Temperature dependence of the inversion degree in three-cation spinel solid solutions: experimental evaluation by XRD

Published online by Cambridge University Press:  22 April 2015

Jacek Podwórny*
Affiliation:
Institute of Ceramics and Building Materials, Refractory Materials Division in Gliwice, ul. Toszecka 99, 44-101 Gliwice, Poland
*
a) Author to whom correspondence should be addressed. Electronic mail: [email protected]

Abstract

The method of degree of inversion calculation presented in the present paper was based on the determination of several temperature-dependent parameters such as: oxygen positional parameter, lattice parameter, cation site occupancies, and a cation–anion distance in tetrahedral and octahedral sites. The theoretical basis of the method as well as the required derivation of formulae and the conditions of its application has been described.

The values of the measured temperature-dependent parameters were used to calculate the degree of inversion vs. temperature in the spinel structure. Initial temperatures of the order–disorder transformation were determined. The described method of investigating the order–disorder phase transformation based on three examples of spinel solid solutions: Mg(Al0.5Fe0.5)2O4, (Mg0.75Ni0.25)Al2O4, and (Mg0.75Co0.25)Al2O4 has been presented. Investigations by means of the high-temperature X-ray diffraction method at temperatures ranging from 25 to 1100 °C were carried out. It has been shown that using the present method, it is possible to determine the distribution of each cation in tetrahedral and octahedral sites at each temperature. In consequence, the unidirectional order–disorder phase transformation as well the bidirectional transformation in the spinel structure can be investigated. The advantages and disadvantages of the method have been discussed and its uncertainties presented.

Type
Technical Articles
Copyright
Copyright © International Centre for Diffraction Data 2015 

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

Carbonin, S., Martignago, F., Menegazzo, G. and Dal Negro, A. (2002). “X-ray single-crystal study of spinels: in situ heating,” Phys. Chem. Miner. 29, 503514.CrossRefGoogle Scholar
Della Giusta, A., Carbonin, S. and Ottonello, G. (1996). “Temperature-dependent disorder in a natural Mg–Al–Fe2+–Fe3+-spinel,” Miner. Mag. 60, 603616.Google Scholar
Henderson, C. M. B., Charnock, J. M. and Plant, D. A. (2007). “Cation occupancies in Mg, Co, Ni, Zn, Al ferrite spinels: a multi-element EXAFS study,” J. Phys.: Condens. Matter 19, 125.Google Scholar
Lavina, B., Salviulo, G. and Della Giusta, A. (2002). “Cation distribution and structure modeling of spinel solid solutions,” Phys. Chem. Miner., 29, 1018.Google Scholar
Martignago, F., Andreozzi, G. B. and Dal Negro, A. (2006). “Thermodynamics and kinetics of cation ordering in natural and synthetic Mg(Al, Fe3+)2O4 spinels from in situ high-temperature X-ray diffraction,” Am. Miner., 91, 306312.Google Scholar
O'Neill, H. St. C. and Navrotsky, A. (1983). “Simple spinels: crystallographic parameters, cation radii, lattice energies and cation distributions,” Am. Mineral 68, 181194.Google Scholar
Podwórny, J. (2013). “XRD based methods of investigation the order – disorder transformation in the spinel structure – a comparative study,” Solid State Phenom . 203–204, 129132.Google Scholar
Podwórny, J., Wojsa, J. and Piotrowski, J. (2004). “High Temperature Behaviour of MgAl2O4, MgCr2O4 and MgFe2O4 Spinels in Relation to their Structure,” Applied Crystallography, (World Scientific Publishing Co. Pte. Ltd.), pp. 403406.Google Scholar
Podwórny, J., Piotrowski, J. and Wojsa, J. (2008). “Investigations into the kinetics and mechanism of gas-solid state processes in MgO–MgR 2O4 (R: Al, Cr, Fe) spinels–SO2–O2 system,” Ceram. Int., 34, 15871593.Google Scholar
Redfern, S. A. T., Harrison, R. J., O'Neill, H. St. C. and Wood, D. R. R. (1999). “Thermodynamics and kinetics of cation ordering in MgAl2O4 spinel up to 1600 °C from in situ neutron diffraction,” Am. Miner., 84, 299310.Google Scholar
Rodríguez-Carvajal, J. (1993). “Recent advances in magnetic structure determination by neutron powder diffraction,” Physica B 192, 5569.Google Scholar
Rodriguez-Carvajal, J. and Roisnel, T. (1998). “FullProf.98 and WinPLOTR: new windows 95/NT applications for diffraction commission for powder diffraction, international union for crystallography,” Newletter 20 (May–AugustGoogle Scholar
Roisnel, T. and Rodríguez-Carvajal, J. (2001). “WinPLOTR: a windows tool for powder diffraction pattern analysis,” Mater. Sci. Forum 378–381, 118123.Google Scholar
Shannon, R. D. (1976). “Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides,” Acta Crystallogr. A 32, 751767.CrossRefGoogle Scholar