Tuning of carrier type, enhancement of Linear magnetoresistance and inducing ferromagnetism at room temperature with Cu doping in Bi2Te3 Topological Insulators

Journal Article · Thu Feb 15 00:00:00 EST 2018 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2017.09.060· OSTI ID:22805375

Singh, Abhishek; Singh, Rahul ^[1]; Patel, T.; Okram, G. S.; Lakhani, A.; Ganeshan, V. ^[2]; Ghosh, A. K. ^[3]; Jha, S. N.; Patil, Swapnil; Chatterjee, Sandip ^[1]

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1. Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005 (India)
2. UGC-DAE Consortium for Scientific Research, Indore, Madhya Pradesh, 452001 (India)
3. Department of Physics, Banaras Hindu University, Varanasi,221005 (India)

Highlights: • With Cu doping in Bi{sub 2}Te{sub 3}, resistivity increases as Fermi level is shifted into valence band with extra scattering centers. • Cu doping tunes the carrier from n to p type, which is attributed to the presence of Te{sub Bi} and Bi{sub Te} antisites. • The observed Linear Magneto resistance is believed to be associated with gapless linear energy spectrum of surface Dirac Fermions. • Cu doping induces room temperature ferromagnetism. - Abstract: Structural, resistivity, thermoelectric power, magneto-transport and magnetic properties of Cu doped Bi{sub 2}Te{sub 3} topological insulators have been investigated. The tuning of charge carriers from n to p type by Cu doping at Te sites of Bi{sub 2}Te{sub 3} is observed both from Hall effect and thermoelectric power measurements. Carrier mobility decreases with the doping of Cu which provides evidence of the movement of Fermi level from bulk conduction band to the bulk valence band. Thermoelectric power also increases with doping of Cu. Moreover, linear magnetoresistance (LMR) is observed at high magnetic field in pure Bi{sub 2}Te{sub 3} which is associated to the gapless topological surface states protected by time reversal symmetry (TRS). Furthermore, doping of non-magnetic Cu induces ferromagnetism at room temperature and also enhances the magnetoresistance.

• OSTI ID: 22805375
• Journal Information: Materials Research Bulletin, Vol. 98; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BISMUTH TELLURIDES
CARRIER MOBILITY
CHARGE CARRIERS
COPPER
DOPED MATERIALS
ENERGY SPECTRA
FERMI LEVEL
FERMIONS
FERROMAGNETISM
HALL EFFECT
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MAGNETORESISTANCE
N-TYPE CONDUCTORS
P-TYPE CONDUCTORS
SCATTERING
TEMPERATURE RANGE 0273-0400 K
TOPOLOGY