Structural phase transitions in Bi2Se3 under high pressure.
Structural phase transitions in Bi2Se3 under high pressure.
复制标题
DOI：
10.1038/srep15939
复制
发表时间：
2015-11-02
影响因子：
4.6
通讯作者：
Mao HK
中科院分区：
文献类型：
--
作者：
Yu Z;Wang L;Hu Q;Zhao J;Yan S;Yang K;Sinogeikin S;Gu G;Mao HK
利用拉曼光谱和角色散X射线衍射（XRD）实验研究了35.6和81.2 GPa压力下硒化铋（Bi 2 Se 3）的压致相变。实验结果表明，该合金经历了从菱面体相（SG：R-3 m）到单斜相（SG：C2/m）再到高压体心四面体相（SG：I4/mmm）的渐进结构演化过程。通过我们的XRD数据证明，在81.2 GPa下，Bi 2Se 3结晶成体心四方晶系结构，而不是最近报道的无序体心立方（BCC）相。此外，第一性原理理论计算支持I4/mmm相Bi 2Se 3可以在高压（>30 GPa）下稳定的观点。值得注意的是，这项工作（两个独立的运行）的Bi 2 Se 3的拉曼光谱仍然是拉曼活性高达~35 GPa。值得注意的是，在27.8GPa下没有观察到无序的BCC相。Bi_2Se_3中Bi和Se原子半径的显著差异可以解释Bi_2Se_3与Bi_2 Te_3和Sb_2 Te_3的结构行为不同的原因。
Raman spectroscopy and angle dispersive X-ray diffraction (XRD) experiments of bismuth selenide (Bi2Se3) have been carried out to pressures of 35.6 and 81.2 GPa, respectively, to explore its pressure-induced phase transformation. The experiments indicate that a progressive structural evolution occurs from an ambient rhombohedra phase (Space group (SG): R-3m) to monoclinic phase (SG: C2/m) and eventually to a high pressure body-centered tetragonal phase (SG: I4/mmm). Evidenced by our XRD data up to 81.2 GPa, the Bi2Se3 crystallizes into body-centered tetragonal structures rather than the recently reported disordered body-centered cubic (BCC) phase. Furthermore, first principles theoretical calculations favor the viewpoint that the I4/mmm phase Bi2Se3 can be stabilized under high pressure (>30 GPa). Remarkably, the Raman spectra of Bi2Se3 from this work (two independent runs) are still Raman active up to ~35 GPa. It is worthy to note that the disordered BCC phase at 27.8 GPa is not observed here. The remarkable difference in atomic radii of Bi and Se in Bi2Se3 may explain why Bi2Se3 shows different structural behavior than isocompounds Bi2Te3 and Sb2Te3.