Antiferromagnetic order induced by gadolinium substitution in Bi2Se3 single crystals

초록

Magnetic topological insulators can serve as a fundamental platform for various spin-based device applications. We report the antiferromagnetic order induced by the magnetic impurity dopants of Gd in GdxBi2-xSe3 and the systematic results with varying the Gd concentration x (= 0.14, 0.20, 0.30, and 0.40). The antiferromagnetic order is demonstrated by the magnetic susceptibility, electrical resistivity, and specific heat measurements. The anomaly observed at T-N = 6K for x >= 0.30 shifts towards lower temperature with increasing the magnetic field, indicative of antiferromagnetic ground state. The Gd substitution into Bi2Se3 enables not only tuning the magnetism from paramagnetic to antiferromagnetic for high x (>= 0.30) but also giving a promising candidate for antiferromagnetic topological insulators. (C) 2015 AIP Publishing LLC.

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