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Title: Ferromagnetism of magnetically doped topological insulators in Cr{sub x}Bi{sub 2−x}Te{sub 3} thin films

We investigated the effect of magnetic doping on magnetic and transport properties of Bi{sub 2}Te{sub 3} thin films. Cr{sub x}Bi{sub 2−x}Te{sub 3} thin films with x = 0.03, 0.14, and 0.29 were grown epitaxially on mica substrate with low surface roughness (∼0.4 nm). It is found that Cr is an electron acceptor in Bi{sub 2}Te{sub 3} and increases the magnetization of Cr{sub x}Bi{sub 2−x}Te{sub 3}. When x = 0.14 and 0.29, ferromagnetism appears in Cr{sub x}Bi{sub 2−x}Te{sub 3} thin films, where anomalous Hall effect and weak localization of magnetoconductance were observed. The Curie temperature, coercivity, and remnant Hall resistance of thin films increase with increasing Cr concentration. The Arrott-Noakes plot demonstrates that the critical mechanism of the ferromagnetism can be described better with 3D-Heisenberg model than with mean field model. Our work may benefit for the practical applications of magnetic topological insulators in spintronics and magnetoelectric devices.
Authors:
; ; ; ;  [1] ;  [1] ;  [2]
  1. Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22410045
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BINDING ENERGY; BISMUTH TELLURIDES; CHROMIUM COMPOUNDS; COERCIVE FORCE; CONCENTRATION RATIO; CURIE POINT; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; ELECTRONS; EPITAXY; FERROMAGNETISM; HALL EFFECT; HEISENBERG MODEL; MAGNETIC PROPERTIES; MAGNETIZATION; MEAN-FIELD THEORY; SUBSTRATES; SURFACES; THIN FILMS