Magnetic and magnetotransport properties of Bi${}_2$Se${}_3$ thin films doped by Eu

Abstract

Structural, magnetic and magnetotransport properties of (Bi${}_{1-x}$Eu${}_x$)${}_2$Se${}_3$ thin films have been studied experimentally as a function of Eu content. The films were synthesized by MBE. It is demonstrated that Eu distribution is not uniform, it enter quint-layers forming inside them plain (pancake-like) areas containing Eu atoms, which sizes and concentration increase with the growth of Eu content. Positive magnetoresistance related to the weak antilocalization was observed up to 15K. The antilocalization was not followed by weak localization as theory predicts for nontrivial topological states. Surprisingly, the features of antilocalization were seen even at Eu content $x$ $=$ 0.21. With the increase of Eu content the transition to ferromagnetic state occurs at $x$ about 0.1 and with the Curie temperature $\approx$ 8K, that rises up to 64K for $x$ $=$ 0.21. At temperatures above 1-2 K, the dephasing length is proportional to $T^{-1/2}$ indicating the dominant contribution of inelastic $e-e$ scattering into electron phase breaking. However, at low temperatures the dephasing length saturates, that could be due to the scattering on magnetic ions.

arXiv comment7 pages, 4 figuers

References in corpus (5)

• Topological Insulators
• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• Crossover between weak localization and weak antilocalization in magnetically doped topological insulator
• Competition between weak localization and antilocalization in topological surface states
• Low temperature Hall effect in bismuth chalcogenides thin films

Cited by in corpus (3)

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• Structural, Surface Morphology and Magneto-Transport properties of Self Flux Grown Eu Doped Bi2Se3 Single Crystal