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A Complete Solid Solution with Rutile‐Type Structure in SiO 2 –GeO 2 System at 12 GPa and 1600°C
Author(s) -
Kulik Eleonora,
Nishiyama Norimasa,
Masuno Atsunobu,
Zubavichus Yan,
Murzin Vadim,
Khramov Evgeny,
Yamada Akihiro,
Ohfuji Hiroaki,
Wille HansChristian,
Irifune Tetsuo,
Katsura Tomoo
Publication year - 2015
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.13859
Subject(s) - stishovite , coesite , rutile , materials science , solid solution , decomposition , germanium , lattice constant , silicon , mineralogy , phase transition , thermodynamics , phase (matter) , analytical chemistry (journal) , crystallography , high pressure , chemistry , geology , metallurgy , diffraction , paleontology , physics , tectonics , organic chemistry , optics , chromatography , eclogite , subduction
High pressure and temperature synthesis of compositions made of (Si 1− x ,Ge x )O 2 where x is equal to 0, 0.1, 0.2, 0.5, 0.7, and 1 was performed at 7–12 GPa and 1200–1600°C using a Kawai‐type high‐pressure apparatus. At 12 GPa and 1600°C, all the run products were composed of a single phase with a rutile structure. The lattice constants increase linearly with the germanium content ( x ), which indicates that the rutile‐type phases in the SiO 2 –GeO 2 system form a complete series of solid solutions at these pressure and temperature conditions. Our experimental results show that thermodynamic equilibrium state was achieved in this system at 12 GPa and 1600°C, but not at 1200°C. At lower pressures (7 and 9 GPa) and 1600°C, we observed the decomposition of (Si 0.5 ,Ge 0.5 )O 2 into SiO 2 ‐rich coesite and GeO 2 ‐rich rutile phases. The silicon content in the rutile structure increases sharply with pressure in the vicinity of the coesite–stishovite phase transition pressure in SiO 2 .