Indexed by: Journal paper

First Author: D Wu

Correspondence Author: G Xu,NL Wang,P Gao

Co-author: L Tong,LY Shi,J Su,GY Zhong,SL Chen,QM Liu

Journal: Physical Review Materials

Included Journals: SCI

Discipline: Science

First-Level Discipline: Physics

Document Type: J

Volume: 3

Issue: 2

Page Number: 24002

ISSN No.: 2475-9953

Date of Publication: 2019-02-11

Impact Factor: 3.337

Abstract: We report a novel quasi-two-dimensional compound of EuTe4 hosting charge density waves (CDW) instability. The compound has a crystallographic structure in a orthorhombic space group Pmmn (No. 59) with cell parameters a=4.6347(2)Å, b=4.5119(2)Å, c=15.6747(10)Å at room temperature. The pristine structure contains consecutive near-square Te sheets separated by corrugated Eu-Te slabs. Upon cooling, the compound experiences a phase transition near 255 K. X-ray crystallographic analysis and transmission electron microscopy measurements reveal strong structural distortions in the low-temperature phase, showing a 1a×3b×2c superstructure with a periodic formation of Te trimers in the monolayer Te sheets, yielding evidence for the formation of CDW order. The charge transport properties show a semiconducting behavior in the CDW state. Density functional theory calculations reveal a Fermi surface nesting-driven instability with a nesting vector in good agreement with the one observed experimentally. Our finding provides a promising system for the study of CDW driven two-dimensional (2D) semiconducting mechanisms, which would shed a light on exploring 2D semiconductors with collective electronic states.

Links to published journals: https://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.3.024002