High-temperature study of octahedral cation exchange in olivine by neutron powder diffraction

Science

Volumn 271, Issue 5256, 1996, Pages 1713-1715

  Henderson, C M B ^a   Knight, K S ^b   Redfern, S A T ^c   Wood, B J ^d  

^a UNIVERSITY OF MANCHESTER   (United Kingdom)

^b RUTHERFORD APPLETON LABORATORY   (United Kingdom)

^c UNIVERSITY OF CAMBRIDGE   (United Kingdom)

^d UNIVERSITY OF BRISTOL   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

CATION EXCHANGE; NEUTRON POWDER DIFFRACTION; OCTAHEDRAL SITE; OLIVINE;

EID: 0029750803     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.271.5256.1713     Document Type: Article

References (24)

1. G E Brown Jr., in Orthosilicates, P. H. Ribbe, Ed (Reviews in Mineralogy, vol. 5, Mineralogical Society of America, Washington, DC, 1980), pp. 275-381
2. F. Princivalle, Mineral Petrol. 43, 121 (1990); G. Ottonello, F, Princivalle, A. Della Giusta, Phys. Chem. Miner. 17, 301 (1990).
3. F. Princivalle, Mineral Petrol. 43, 121 (1990); G. Ottonello, F, Princivalle, A. Della Giusta, Phys. Chem. Miner. 17, 301 (1990).
4. T. Akamatsu et al., Phys. Chem Miner. 16, 105 (1988)
5. N. Aikawa, M. Kumazawa, M Tokonami, ibid. 12, 1 (1985)
6. T. Akamatsu and M. Kumazawa, ibid. 19, 423 (1993).
7. G. Artioli, M. Bellotto, B. Palosz, Powder Diffr. 9, 63 (1994)
8. J. R. Smyth and R. M. Hazen, Am. Mineral. 58, 588 (1973); G. E. Brown and C. T. Prewitt, ibid , p. 577
9. J. R. Smyth and R. M. Hazen, Am. Mineral. 58, 588 (1973); G. E. Brown and C. T. Prewitt, ibid , p. 577
10. M2 (molar ratios).
11. T. Motoyama and T. Matsumoto, Mineral. J. 14, 338 (1989).
12. G. Artioli, R. Rinaldi, C. C. Wilson, P. F. Zanazzi, Am. Mineral 80, 197 (1995); R. Rinaldi and C. C. Wilson, Solid State Commun 97, 395 (1996).
13. G. Artioli, R. Rinaldi, C. C. Wilson, P. F. Zanazzi, Am. Mineral 80, 197 (1995); R. Rinaldi and C. C. Wilson, Solid State Commun 97, 395 (1996).
14. R. I. Smith, S. Hull, A. R Armstrong, Mater. Sci Forum 166-169, 251 (1994).
15. 2-CO gas mixtures about 1 log unit more oxidizing than the Fe-FeO buffer and quenched within the reducing gas atmosphere to below 500°C in <1 min. About 3 5 g of each was prepared. Both samples were studied by x-ray powder diffraction and were found to be phase pure, with narrow peaks showing that they were well crystallized and homogeneous Each sample was loaded into a thin-walled quartz glass tube, with silica wool separating the sample from either Fe-FeO buffer (Fe-Mn sample) or Ni-NiO buffer (Mn-Mg) The tubes were then evacuated and sealed, placed in vanadium cans, and mounted inside a vanadium furnace assembly, the whole of which was evacuated to a residual P of about 0.05 Pa. For the Fe-Mn sample, isothermal diffraction patterns were collected for 2 hours each upon heating and for 1/2 hour each upon cooling, Mg-Mn data were collected for 1 hour upon heating Structural data were obtained by Rietveld refinement. For the Fe-Mn sample, at each T between 400° and 750°C, diffraction patterns were collected in four 1/2-hour periods. Some of these isothermal data sets were refined separately, but no differences in srte populations were observed
16. D values of about 3 to 4.5%.
17. M. Miyamoto and H. Takeda, Nature 303, 602 (1983).
18. H. Annersten, J Adetunji, A Filippidis, Am. Mineral 69, 1110 (1984)
19. C. A. Francis and P H Ribbe, ibid 65, 1263 (1980)
20. M. Hirschmann, B W. Evans, H. Yang, ibid 79, 862 (1994).
21. M S Ghiorso, B W Evans, M. M. Hirschmann, H Yang, ibid 80, 502 (1995)
22. J A Sykes-Nord and G. M. Molin, ibid. 78, 921 (1993).
23. G. M Molin, S. K. Saxena, E. Brizi, Earth Planet. Sci Lett 105, 260 (1991).
24. We thank Rutherford Appleton Laboratory for research grant RB6035 and R. Rinaldi and an anonymous reviewer for constructive critical comments