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Preparation and Optical Properties of Polycrystalline Aluminum Germanate

Published online by Cambridge University Press:  15 February 2011

S. Prochazka  and
G. A. Slack
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Extract

Aluminum germanate, the germanium analog of mullite, 3 AlO2O3 . 2 GeO2, was first prepared by Gelsdorf, Muller-Hesse and Schweite (Ref. 1), who demonstrated that both partial and complete substitution of SiO2 by GeO2 in mullite was possible. They also determined the lattice constants of the solid solutions. The following studies reported some physical properties of aluminum germanate such as density (Ref. 2) optical constants (Ref. 2) crystal structure (Ref. 3) and I. R. absorption (Ref. 4). Phase equilibria in the system AlO2O3−GeO2 were investigated by Miller et al. (Ref. 5) and Perez-y-Jorba (Ref. 6). The ratter author found several compounds of which germanium mullite was the most stable and showed a relatively wide compositional range. Miller et al. observed only 3 Al2O3 . 2 GeO2 with no evidence of solid solutions. The compound was reported to melt incongruently at 1530° C. Recently Yamaguchi et al. (Ref. 7) prepared aluminum germanates of a wide range of stoichiometry from alkyl oxides and found, in addition to germanium mullite, the compound Al2O3−2GeO2 which was stable between 1190° and 1310° C. The authors also report infrared absorption spectra.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 32: Symposium B – Better Ceramics Through Chemistry I , 1984 , 245
Copyright
Copyright © Materials Research Society 1984

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References

REFERENCES

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