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Title: Magnetotransport study of (Sb1-xBix)2Te3 thin films on mica substrate for ideal topological insulator

In this study, we deposited high quality (Sb1–xBix)2Te3 on mica substrate by molecular beam epitaxy and investigated their magnetotransport properties. It is found that the average surface roughness of thin films is lower than 2 nm. Moreover, a local maxima on the sheet resistance is obtained with x = 0.043, indicating a minimization of bulk conductivity at this composition. For (Sb0.957Bi0.043)2Te3, weak antilocalization with coefficient of -0.43 is observed, confirming the existence of 2D surface states. Moreover Shubnikov-de Hass oscillation behavior occurs under high magnetic field. The 2D carrier density is then determined as 0.81 × 1016 m–2, which is lower than that of most TIs reported previously, indicating that (Sb0.957Bi0.043)2Te3 is close to ideal TI composition of which the Dirac point and Fermi surface cross within the bulk bandgap. Our results thus demonstrate the best estimated composition for ideal TI is close to (Sb0.957Bi0.043)2Te3 and will be helpful for designing TI-based devices.
Authors:
 [1] ;  [1] ;  [2] ;  [1]
  1. Iowa State Univ., Ames, IA (United States)
  2. Iowa State Univ., Ames, IA (United States); Ames Lab., Ames, IA (United States)
Publication Date:
Report Number(s):
IS-J-8879
Journal ID: ISSN 2158-3226; AAIDBI; TRN: US1600404
Grant/Contract Number:
1201883; AC02-07CH11358
Type:
Published Article
Journal Name:
AIP Advances
Additional Journal Information:
Journal Volume: 6; Journal Issue: 5; Journal ID: ISSN 2158-3226
Publisher:
American Institute of Physics (AIP)
Research Org:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; surface states; magnetic fields; electrical resistivity; epitaxy; carrier density
OSTI Identifier:
1239704
Alternate Identifier(s):
OSTI ID: 1240746