High-Pressure Phase Transitions and Structures of Topological Insulator BiTeI
Being a giant bulk Rashba semiconductor, the ambient-pressure phase of BiTeI was predicted to transform into a topological insulator under pressure at 1.7–4.1 GPa [ Nat. Commun. 2012, 3, 679 ]. Because the structure governs the new quantum state of matter, it is essential to establish the high-press...
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Veröffentlicht in: | Journal of physical chemistry. C 2013-12, Vol.117 (48), p.25677-25683 |
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Hauptverfasser: | , , , , , , , , , , , |
Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | Being a giant bulk Rashba semiconductor, the ambient-pressure phase of BiTeI was predicted to transform into a topological insulator under pressure at 1.7–4.1 GPa [ Nat. Commun. 2012, 3, 679 ]. Because the structure governs the new quantum state of matter, it is essential to establish the high-pressure phase transitions and structures of BiTeI for better understanding its topological nature. Here, we report a joint theoretical and experimental study up to 30 GPa to uncover two orthorhombic high-pressure phases of Pnma and P4/nmm structures named phases II and III, respectively. Phases II (stable at 8.8–18.9 GPa) and III (stable at >18.9 GPa) were first predicted by our first-principles structure prediction calculations based on the calypso method and subsequently confirmed by our high-pressure powder X-ray diffraction experiment. Phase II can be regarded as a partially ionic structure, consisting of positively charged (BiTe)+ ladders and negatively charged I– ions. Phase III is a typical ionic structure characterized by interconnected cubic building blocks of Te–Bi–I stacking. Application of pressures up to 30 GPa tuned effectively the electronic properties of BiTeI from a topological insulator to a normal semiconductor and eventually a metal having a potential of superconductivity. |
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ISSN: | 1932-7447 1932-7455 |
DOI: | 10.1021/jp409824g |