Phase relations in silicon and germanium nitrides up to 98 GPa and 2400°C
Phase relations in silicon and germanium nitrides up to 98 GPa and 2400°C
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DOI：
10.1111/jace.16063
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发表时间：
2018-09
影响因子：
3.9
通讯作者：
N. Nishiyama;J. Langer;T. Sakai;Y. Kojima;A. Holzheid;N. A. Gaida;E. Kulik;N. Hirao;S. Kawaguchi;T. Irifune;Y. Ohishi
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作者：
N. Nishiyama;J. Langer;T. Sakai;Y. Kojima;A. Holzheid;N. A. Gaida;E. Kulik;N. Hirao;S. Kawaguchi;T. Irifune;Y. Ohishi
利用Kawai型多对顶砧装置和激光加热金刚石对顶砧装置结合同步辐射研究了氮化硅和氮化锗（Si 3 N4和Ge 3 N4）的相关系。在两种组合物中观察到从β相到γ相（立方尖晶石型结构）的压力诱导相变。在12.4 GPa和1800°C下，我们观察到Si 3 N4中β和γ相共存，而在10 GPa以上的压力下观察到单相γ-Ge 3 N4的出现。我们在高压下的观察表明，γ-Si 3 N4和γ-Ge 3 N4具有宽的稳定域，在高达98 GPa和2400°C的温度下，在两种成分中均未观察到后尖晶石转变。利用这些材料的室温压缩曲线，确定了体积模量（K 0）及其压力导数（K′0）：γ-Si 3 N4的K 0 = 317（16）GPa和K ′0= 6.0（8）; γ-Ge 3 N4的K 0 = 254（13）GPa和K ′0= 6.0（7）。
Phase relations in silicon and germanium nitrides (Si3N4and Ge3N4) 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 Si3N4at 12.4 GPa and 1800°C, while the appearance of single phase γ‐Ge3N4was observed at pressures above 10 GPa. Our observations under higher pressures revealed that γ‐Si3N4and γ‐Ge3N4have 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 (K0) and their pressure derivatives (K′0) were determined:K0= 317 (16) GPa andK′0= 6.0 (8) for γ‐Si3N4;K0= 254 (13) GPa andK′0= 6.0 (7) for γ‐Ge3N4.