New high-pressure phase relations in CaSnO3
New high-pressure phase relations in CaSnO3
复制标题
DOI：
10.2138/am.2006.2221
复制
发表时间：
2006-11
影响因子：
3.1
通讯作者：
T. Tsuchiya;J. Tsuchiya
中科院分区：
文献类型：
--
作者：
T. Tsuchiya;J. Tsuchiya
摘要采用密度泛函理论静态晶格能计算方法研究了CaSnO 3体系的高压相稳定性。我们已经确定了该系统中的六个相变：钙钛矿后钙钛矿，钙钛矿后钙钛矿-B2+cotunnite在CaSiO 3中，B1-B2在CaO中，钙钛矿-黄铁矿，pyrerecurs thorhombic-I，和orthorhombic-I-cotunnite在SnO 2。我们的研究结果表明，一个新的高压相序列的钙钛矿→后钙钛矿→ B2 + cotunnite。后钙钛矿转变发生在约12 GPa，约2.5%的体积减少，然后它分解成B2 CaO和cotunnite SnO 2的氧化物混合物在约70 GPa，约8.1%的体积减少。结果还预测了几个百分点的体积速度变化在这些相位变化。
Abstract High-pressure phase stabilities of the CaSnO3 system were investigated using density functional theory static lattice energy calculations. We have identified six phase changes in this system: perovskitepost-perovskite, post-perovskite-B2+cotunnite in CaSiO3, B1-B2 in CaO, cassiterite-pyrite, pyriteorthorhombic-I, and orthorhombic-I-cotunnite in SnO2. Our results demonstrate a new high-pressure phase sequence of perovskite → post-perovskite → B2 + cotunnite. The post-perovskite transformation occurs at ~12 GPa with ~2.5% volume reduction and then it decomposes into the oxide mixture of B2 CaO and cotunnite SnO2 at ~70 GPa with 8.1% volume reduction. The results also predict a few percent bulk velocity variations across these phase changes.