Formation and Structure of a Dense Octahedral Glass

M. Guthrie, C. A. Tulk, C. J. Benmore, J. Xu, J. L. Yarger, D. D. Klug, J. S. Tse, H-k. Mao, R. J. Hemley
2004 Physical Review Letters  
We have performed in situ x-ray and neutron-diffraction measurements, and molecular dynamics simulations, of GeO 2 , an archetypal network-forming glass under pressure. Below 5 GPa, additional atoms encroaching on the first tetrahedral shell are seen to be a precursor of local coordination change. Between 6 and 10 GPa, we observe structures with a constant average coordination of 5, indicating a new metastable, intermediate form of the glass. At 15 GPa, the structure of a fully octahedral glass
more » ... ly octahedral glass has been measured. This structure is not retained upon decompression and, therefore, must be studied in situ.
doi:10.1103/physrevlett.93.115502 pmid:15447351 fatcat:lusl5npn3bct5ip6igyskef7pe