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The influence of next nearest neighbours on cation radii in spinels: the example of the Co3O4-CoCr2O4 solid solution

Published online by Cambridge University Press:  05 July 2018

H. St. C. O’Neill
H. St. C. O’Neill*
Affiliation:
Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia
*
* E-mail: hugh.oneill@anu.edu.au
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Abstract

Lattice parameters and crystal structures of the synthetic spinels Co3O4, CoCr2O4, and solid solutions in the binary join Co3O4-CoCr2O4, have been determined by powder X-ray diffraction structural refinements. In all these spinels the cation distribution is completely normal at room temperature, and the tetrahedrally coordinated cation site is occupied only by Co2+. The ionic radius of Co2+(tet) increases from 0.556(3) in Co3O4 to 0.599(4) in CoCr2O4. In the spinel structure, the interatomic distance between the tetrahedral cations and oxygen are geometrically independent of those between the octahedral cations and oxygen; thus the variation in effective ionic radii is ascribed to next-nearest neighbour effects, induced by covalent tendencies in the low-spin Co3+-O bond. The results demonstrate that the assumption of constant ionic radii even within an isomorphic group such as the oxide spinels needs to be made with caution.

Keywords

spinelXRD dataionic radii.
Type
Research Article
Information
Mineralogical Magazine , Volume 67 , Issue 3 , June 2003 , pp. 547 - 554
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2003

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References

Andreozzi, G.B., Princivalle, F., Skogby, H. and Della Giusta, A. (2000) Cation ordering and structural variations with temperature in MgAl2O4 spinel: an X-ray single-crystal study. American Mineralogist, 85, 1164–1171.CrossRefGoogle Scholar
Burns, R.G. (1993) Mineralogical Applications of Crystal Field Theory (2nd edition). Cambridge University Press, Cambridge, UK, 551 pp.CrossRefGoogle Scholar
Della Giusta, A. and Ottonello, G. (1993) Energy and long-range disorder in simple spinels. Physics and Chemistry of Minerals, 20, 228—241.CrossRefGoogle Scholar
Fiorani, D. and Viticoli, S. (1980) Investigation on magnetically dilute CoxZn1-xRh2O4 spinel solid solution. Journal of the Physics and Chemistry of Solids, 41, 1041—1045.CrossRefGoogle Scholar
Hazen, R.M., Downs, R.T., Finger, L.W. and Ko, J. (1993) Crystal chemistry of ferromagnesian silicate spinels: evidence for Mg-Si disorder. American Mineralogist, 78, 1320—1323.Google Scholar
Hill, R.J., Craig, J.R. and Gibbs, G.V. (1979) Systematics of the spinel structure type. Physics and Chemistry ofMinerals, 4, 317—339.CrossRefGoogle Scholar
Knop, O., Reid, I.G., Sutarno and Nakagawa, Y. (1968) Chalkogenides of the transition elements. VI. X-ray, neutron, and magnetic investigation of the spinels Co3O4, NiCo2O4 , Co3S4, and NiCo2S4. Canadian Journal of Chemistry, 46, 3463—3476.Google Scholar
Lavina, B., Salviulo, G. and Della Giusta, A. (2002) Cation distribution and structure modelling of spinel solid solutions. Physics and Chemistry of Minerals, 29, 10—18.CrossRefGoogle Scholar
Liu, X. and Prewitt, C.T. (1990) High-temperature X-ray diffraction study of Co3O4: Transition from normal to disordered spinel. Physics and Chemistry of Minerals, 17, 168—172.CrossRefGoogle Scholar
Naidu, K. (1978) Thermodynamics of spinel solid solutions: the systems Co3O4–CoAl2O4 and Co3O4–CoCr2O4. MSc thesis, University of Toronto, Canada.Google Scholar
O’Neill, H.St.C. (1985) Thermodynamics of Co3O4: a possible electron spin unpairing transition in Co3+. Physics and Chemistry of Minerals, 12, 149—154.CrossRefGoogle Scholar
O’Neill, H.St.C. (1994) Temperature dependence of the cation distribution in CoAl2O4 spinel. European Journal of Mineralogy, 6, 603—609.CrossRefGoogle Scholar
O’Neill, H.St.C. (1997) Kinetics of the intersite cation exchange in MgAl2O4 spinels: the influence of nonstoichiometry. P. 153 in: Seventh Annual V. M. Goldschmidt Conference, LPI Contribution no. 921, Lunar and Planetary Institute, Houston, Texas, USA.Google Scholar
O’Neill, H.St.C. and Dollase, W.A. (1994) Crystal structures and cation distributions in simple spinels from powder XRD structural refinements: MgCr2O4, ZnCr2O4, Fe3O4, and the temperature dependence of the cation distribution in ZnAl2O4. Physics and Chemistry of Minerals, 20, 541—555.CrossRefGoogle Scholar
O’Neill, H.St.C. and Navrotsky, A. (1983) Simple spinels: Crystallographic parameters, cation radii, lattice energies, and cation distribution. American Mineralogist, 68, 181—194.Google Scholar
O’Neill, H.St.C. and Navrotsky, A. (1984) Cation distributions and thermodynamic properties ofbinary spinel solid solutions. American Mineralogist, 69, 733—753.Google Scholar
O’Neill, H.St.C., Dollase, W.A. and Ross, C.R. II (1991) Temperature dependence of the cation distribution in nickel aluminate (NiAl2O4) spinel: a powder XRD study. Physics and Chemistry of Minerals, 18, 302—319.CrossRefGoogle Scholar
Ottonello, G. (1986) Energetics of multiple oxides with spinel structure. Physics and Chemistry of Minerals, 13, 79–90.CrossRefGoogle Scholar
Pauling, L. (1927) The sizes of ions and the structure of ionic crystals. Journal of the American Chemical Society, 49, 765—790.CrossRefGoogle Scholar
Redfern, S.A.T., Harrison, R.J., O’Neill, H.St.C. and Wood, D.D.R. (1999) Thermodynamics and kinetics of cation ordering in MgAl2O4 spinel up to 1600°C from in situ neutron diffraction. American Mineralogist, 84, 299—310.CrossRefGoogle Scholar
Roth, W.L. (1964) The magnetic structure of Co3O4. Journal of the Physics and Chemistry of Solids, 25, 1—10.CrossRefGoogle Scholar
Shannon, R.D. and Prewitt, C.T. (1969) Effective ionic radii in oxides and fluorides. Acta Crystallographica, B25, 925—946.CrossRefGoogle Scholar
Shannon, R.D. (1976) Effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, A32, 751—767.CrossRefGoogle Scholar
Wiles, D.B. and Young, R.A. (1981) A new computer program for Rietveld analysis of X-ray powder d iffraction patterns. Journal of Applied Crystallography, 14, 149—151.CrossRefGoogle Scholar