First-Principles Calculations of Phase Transition and Stability of Si2CN4 under High Pressure
First-Principles Calculations of Phase Transition and Stability of Si2CN4 under High Pressure
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Si2CN4 高压下相变和稳定性的第一性原理计算
DOI：
10.1088/0256-307x/26/1/016403
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发表时间：
2009-01-01
影响因子：
3.5
通讯作者：
He Ju-Long
中科院分区：
文献类型：
--
作者：
Du Hui-Jing;Guo Li-Cong;He Ju-Long
通过第一性原理计算研究了高压下 Si2CN4 多晶型物的压力诱导相变和稳定性。结果表明，热力学方法预测α-Si2CN4和β-Si2CN4向立方脊柱相的相变压力分别为29.9 GPa和27.5 GPa。在环境条件下，所有三种 Si2CN4 多晶型物都是亚稳态的，具有正的生成焓。与 Si3N4 多晶型物的稳定性不同，α-Si2CN4 比 β 相更稳定。
A pressure-induced phase transition and stability in Si2CN4 polymorphs under high pressure are studied by first-principles calculations. The result shows that the phase transition pressure of alpha- and beta-Si2CN4 to the cubic spinal phase is 29.9 GPa and 27.5 GPa predicted by thermodynamic method respectively. Under ambient condition, all of the three Si2CN4 polymorphs are metastable with positive formation enthalpy. Unlike the stability of Si3N4 polymorphs, alpha-Si2CN4 is more stable than the beta phase.