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Phase relations in silicon and germanium nitrides up to 98 GPa and 2400°C
Author(s) -
Nishiyama Norimasa,
Langer Julia,
Sakai Takeshi,
Kojima Yohei,
Holzheid Astrid,
Gaida Nico A.,
Kulik Eleonora,
Hirao Naohisa,
Kawaguchi Saori I.,
Irifune Tetsuo,
Ohishi Yasuo
Publication year - 2019
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.16063
Subject(s) - germanium , diamond anvil cell , materials science , silicon , phase (matter) , nitride , phase transition , crystallography , silicon nitride , analytical chemistry (journal) , synchrotron radiation , spinel , bulk modulus , mineralogy , high pressure , chemistry , thermodynamics , metallurgy , nanotechnology , optics , physics , organic chemistry , layer (electronics) , chromatography , composite material
Phase relations in silicon and germanium nitrides (Si 3 N 4 and Ge 3 N 4 ) were investigated using a Kawai‐type multianvil apparatus and a laser‐heated diamond anvil cell combined with a synchrotron radiation. The pressure‐induced phase transition from the β to γ (cubic spinel‐type structure) phase was observed in both compositions. We observed the coexistence of the β and γ phases in Si 3 N 4 at 12.4 GPa and 1800°C, while the appearance of single phase γ‐Ge 3 N 4 was observed at pressures above 10 GPa. Our observations under higher pressures revealed that γ‐Si 3 N 4 and γ‐Ge 3 N 4 have wide stability fields and no postspinel transition was observed up to 98 GPa and 2400°C in both compositions. Using the room‐temperature compression curves of these materials, the bulk moduli ( K 0 ) and their pressure derivatives ( K ′ 0 ) were determined: K 0 = 317 (16) GPa and K ′ 0 = 6.0 (8) for γ‐Si 3 N 4 ; K 0 = 254 (13) GPa and K ′ 0 = 6.0 (7) for γ‐Ge 3 N 4 .