Universal phase transitions of B1-structured stoichiometric transition metal carbides.
Universal phase transitions of B1-structured stoichiometric transition metal carbides.
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DOI：
10.1021/ic200356x
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发表时间：
2010-11
影响因子：
4.6
通讯作者：
Zhisheng Zhao;Xiang‐Feng Zhou;Li-Min Wang;Bo Xu;Julong He;Zhongyuan Liu;Hui-Tian Wang;Yongjun Tian-Yon
中科院分区：
文献类型：
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作者：
Zhisheng Zhao;Xiang‐Feng Zhou;Li-Min Wang;Bo Xu;Julong He;Zhongyuan Liu;Hui-Tian Wang;Yongjun Tian-Yon
用从头算方法系统地研究了B1型化学计量过渡金属碳化物(TMCs，Tm=Ti，Zr，Hf，V，Nb，Ta)的高压相变。当受压时，这些碳化物沿着两条新的相变路径发生普遍相变，即B1→扭曲的TiI(TLi‘)→TiI和/或B1→扭曲的TiB(TiB’)→TiB。这两条路线可以共存，可能是因为在相应的压力下，新相之间存在微小的热焓差异。四个新相是由B1结构母相在压力作用下的原子滑移形成的。在完全释放压力后，以TiC为代表的TMCs，只有其新的TLi‘型相在力学和动力学上是稳定的，并且可以恢复。
The high-pressure phase transitions of B1-structured stoichiometric transition metal carbides (TMCs, TM = Ti, Zr, Hf, V, Nb, and Ta) were systematically investigated using ab initio calculations. These carbides underwent universal phase transitions along two novel phase-transition routes, namely, B1 → distorted TlI (TlI') → TlI and/or B1 → distorted TiB (TiB') → TiB, when subjected to pressure. The two routes can coexist possibly because of the tiny enthalpy differences between the new phases under corresponding pressures. Four new phases result from atomic slips of the B1-structured parent phases under pressure. After completely releasing the pressure, taking TiC as representative of TMCs, only its new TlI'-type phase is mechanically and dynamically stable, and may be recovered.