Details

Autor(en) / Beteiligte

• Cai, Weizhao
• He, Jiangang
• Li, Hao
• Zhang, Rong
• Zhang, Dongzhou
• Chung, Duck Young
• Bhowmick, Tushar
• Wolverton, Christopher
• Kanatzidis, Mercouri G.
• Deemyad, Shanti

Titel

Pressure-induced ferroelectric-like transition creates a polar metal in defect antiperovskites Hg3Te2X2 (X = Cl, Br)

Ist Teil von

• Nature communications, 2021-03, Vol.12 (1), p.1509-1509, Article 1509

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Ferroelectricity is typically suppressed under hydrostatic compression because the short-range repulsions, which favor the nonpolar phase, increase more rapidly than the long-range interactions, which prefer the ferroelectric phase. Here, based on single-crystal X-ray diffraction and density-functional theory, we provide evidence of a ferroelectric-like transition from phase I 2 1 3 to R 3 induced by pressure in two isostructural defect antiperovskites Hg 3 Te 2 Cl 2 (15.5 GPa) and Hg 3 Te 2 Br 2 (17.5 GPa). First-principles calculations show that this transition is attributed to pressure-induced softening of the infrared phonon mode Γ 4 , similar to the archetypal ferroelectric material BaTiO 3 at ambient pressure. Additionally, we observe a gradual band-gap closing from ~2.5 eV to metallic-like state of Hg 3 Te 2 Br 2 with an unexpectedly stable R 3 phase even after semiconductor-to-metal transition. This study demonstrates the possibility of emergence of polar metal under pressure in this class of materials and establishes the possibility of pressure-induced ferroelectric-like transition in perovskite-related systems. Generally, ferroelectricity in ABO 3 perovskites is suppressed by hydrostatic compression, but the evidence for pressure-induced ferroelectricity remains elusive. Here, the authors find a direct ferroelectric-like structural transition induced by pressure in defect antiperovskites.