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High-pressure phase transformation of BeGa2O4

Published online by Cambridge University Press:  31 January 2011

K. Nakamura
Affiliation:
Government Industrial Research Institute, Nagoya, Hirate-cho, Kita-ku, Nagoya 462, Japan
M. Machida
Affiliation:
Government Industrial Research Institute, Nagoya, Hirate-cho, Kita-ku, Nagoya 462, Japan
M.E. Brito
Affiliation:
Government Industrial Research Institute, Nagoya, Hirate-cho, Kita-ku, Nagoya 462, Japan
H. Tabata
Affiliation:
Government Industrial Research Institute, Nagoya, Hirate-cho, Kita-ku, Nagoya 462, Japan
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Abstract

High-pressure phase transformation of beryllium gallium oxide (BeGa2O4) has been studied. Applying high pressure at elevated temperatures to the original hexagonal BeGa2O4 (β–Si3N4-type structure), a high-pressure modification with orthorhombic structure (olivine-type structure) was obtained, i.e., o-BeGa2O4. Lattice parameters of the new phase were determined to be a = 0.5698, b = 0.9759, and c = 0.4551 nm. The pressure and temperature ranges where the high-pressure phase was observed are 3.5 to 7.5 GPa and 800 to 1600 °C, respectively. A tentative pressure-temperature phase diagram for BeGa2O4 was proposed. Transformation is not straightforward; decomposition of the original phase into single oxides and their recombination to form o-BeGa2O4 are necessary. This process seems to apply in both ways, formation and decomposition of the high-pressure phase. The stability of the high-pressure phase is explained in terms of the total molar volume for the phase, the result of summing up molar volumes of constituent compounds. This is the first known report on transformation of β–Si3N4-type structure into a denser structure.

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Articles
Copyright
Copyright © Materials Research Society 1993

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References

REFERENCES

1Wyckoff, R.W. G.Crystal Structure, 2nd ed. (Interscience Publishers, New York, 1965), Vol. 3.Google Scholar
2Kugimiya, K. and Steinfink, H.Inorg. Chem. 7, 1762 (1968).Google Scholar
3Wells, A. F.Structural Inorganic Chemistry, 4th ed. (Clarendon Press, Oxford, 1975).Google Scholar
4Harris, L.A. and Yakel, H.L.Acta Crystallogr. 22, 354 (1967).CrossRefGoogle Scholar
5Tabata, H.Ishii, E. and Okuda, H. in 24th Symp. on Artificial Crystals, Octobe r 1979, Sendai,Japan (The Chemical Society of Japan, Tokyo, 1979), p. 93.Google Scholar
6Machida, M.Tabata, H.Kawakami, S. and Ishii, E.J. Appl. Crystallogr. 18, 366 (1985).CrossRefGoogle Scholar
7Shannon, R.D. and Prewitt, C.T.Act a Crystallogr. B25, 925 (1969).Google Scholar
8Whittaker, E. J. W. and Muntus, R.Geochim. Cosmochim. Acta 34, 945 (1970).Google Scholar
9Tabata, H.Ishii, E. and Okuda, H.J. Ceram. Soc. Jpn. 89, 23 (1981).Google Scholar
10Schweizer, M. and Miiller-Buschbaum, Hk., Z. Naturforsch. 34B, 1067 (1979).Google Scholar
11Ruddlesden, S. N. and Popper, P.Act a Crystallogr. 11, 465 (1958).Google Scholar
12Thompson, D. S. and Pratt, P. L.Sci.Ceram. 3, 33 (1967).Google Scholar
13Progress in Nitrogen Ceramics, edited by Riley, F. L. NATO ASI Series, series E No. 65 (Martinus Nijhoff Publishers, The Hague, Netherlands, 1983).CrossRefGoogle Scholar
14Silicon Nitride-I (Ceramics Research in Japan, Vol. 1), edited by Somiya, S.Mitomo, M. and Yoshimura, M. (Elsevier Science Publishers, Essex, 1989).Google Scholar
15Jeffrey, G.A.Parry, G.S. and Mozzi, R.L.J. Chem. Phys. 25, 1024 (1956).Google Scholar
16Swanson, H.E.Fuyat, R.K. and Ugrinic, G.M.Natl. Bur. Stand. Circ. 539, 75 (1955).Google Scholar
17Geller, S.J. Chem. Phys. 33, 676 (1960).Google Scholar
18Stishov, S.M. and Belov, N. V.Dok. Akad. Nauk. SSSR 143, 951 (1961).Google Scholar
19Preisinger, A.Naturwissenschaften 49, 345 (1962).Google Scholar
20Butler, E.Philos. Mag. 24, 829 (1971).CrossRefGoogle Scholar
21Rouxel, T.Wakai, F.Brito, M.E.Iwamoto, A. and Izaki, K. accepted for publication in J. Europ. Ceram. Soc.Google Scholar
22Gueguen, Y.Bull. Mineral. 102, 178 (1979).Google Scholar
23Gaboriaud, R. J.Darot, M.Gueguen, Y. and Woirgard, J.Phys. Chem. Mineral. 7, 100 (1981).Google Scholar
24Young, C. III , Am. J. Sci. 267, 841 (1969).CrossRefGoogle Scholar