Zinc-blende to rocksalt transition in SiC in a laser-heated diamond-anvil cell
Zinc-blende to rocksalt transition in SiC in a laser-heated diamond-anvil cell
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DOI：
10.1103/physrevb.95.134108
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发表时间：
2017-04-18
影响因子：
3.7
通讯作者：
Lee, Kanani K. M.
中科院分区：
文献类型：
--
作者：
Daviau, Kierstin;Lee, Kanani K. M.
我们探索了碳化硅 (SiC) 的常压闪锌矿多晶型 (B3) 结构在高压和高温下转变为岩盐 (B1) 结构的稳定性。我们发现，当加热到中等高温时，发生的转变类似于之前测量的 40 GPa。较低的转变压力与大量从头计算中预测的转变压力一致。我们发现在整个转变过程中体积下降了大约 17%，并且在地层压力较高时体积下降增加，这表明这种转变是体积驱动的，产生了几乎与压力无关的克拉佩龙斜率。在碳化硅暴露于极端条件的应用中，例如工业应用或行星内部，在压力下发生的这种急剧的密度增加是重要的考虑因素。
We explore the stability of the ambient pressure zinc-blende polymorph (B3) structure of silicon carbide (SiC) at high pressures and temperatures where it transforms to the rocksalt (B1) structure. We find that the transition occurs similar to 40 GPa lower than previously measured when heated to moderately high temperatures. Alower transition pressure is consistent with the transition pressures predicted in numerous ab initio computations. We find a large volume decrease across the transition of similar to 17%, with the volume drop increasing at higher formation pressures, suggesting this transition is volume driven yielding a nearly pressure-independent Clapeyron slope. Such a dramatic density increase occurring at pressure is important to consider in applications where SiC is exposed to extreme conditions, such as in industrial applications or planetary interiors.