Indexed by: Journal paper

First Author: Zhimo Zhang

Correspondence Author: Wenhao Zhang,Ying-Shuang Fu

Co-author: Gang Xu,Zijin Ye,Lin Gu,Qinghua Zhang,Fanqi Meng,Rui Li,Min Cai

Journal: Physical Review Materials

Included Journals: SCI

Discipline: Science

First-Level Discipline: Physics

Document Type: J

Volume: 4

Issue: 12

Page Number: 125003

ISSN No.: 2475-9953

Date of Publication: 2020-12-29

Impact Factor: 3.989

Abstract: We present an investigation on the controlled growth of epitaxial iron telluride films of multiple phases by molecular beam epitaxy. By optimizing the substrate temperature, we fabricate different phases of α-FeTe, β-FeTe, and FeTe2, respectively, whose crystalline morphologies are determined by means of in situ scanning tunneling microscopy/spectroscopy and ex situ scanning transmission electron microscopy. While both α- and β-FeTe films are metallic, we uncover a ∼185- and 65-mV semiconducting band gap for the (100) and (011) facets of FeTe2 film, respectively, with the former one being compatible with the first principles calculations. Moreover, for FeTe2, we observe reduced gaps with enhanced conductance in the vicinity of edge boundaries, which are dependent on the geometries of step orientation and possibly in correlation to the magnetic anisotropy with structural distortion. Our study provides insight into the controllable synthesis of Fe-Te compounds with variation of stoichiometries and surface terminations, which may generalize to other epitaxial Fe chalcogenide films.