title: Magnetic Transition to Antiferromagnetic Phase in Gadolinium Substituted Topological Insulator Bi2Te3.
abstract: There are many interests to achieve long-range magnetic order in topological insulators of Bi2Se3 or Bi2Te3 by doping magnetic transition metals such as Fe and Mn. The transition metals act as not only magnetic dopants but also electric dopants because they are usually divalent. However, if the doping elements are rare-earth metals such as Gd, which are trivalent, only magnetic moments can be introduced. We fabricated single crystals of Bi2-xGdxTe3 (0 ≤ × ≤ 0.2), in which we observed magnetic phase change from paramagnetic (PM) to antiferromagnetic (AFM) phase by increasing x. This PM-to-AFM phase transition agrees with the density functional theory calculations showing a weak and short-ranged Gd-Gd AFM coupling via the intervening Te ions. The critical point corresponding to the magnetic phase transition is x = 0.09, where large linear magnetoresistance and highly anisotropic Shubnikov-de Haas oscillations are observed. These results are discussed with two-dimensional properties of topological surface state electrons.
authors.affiliation: Department of Physics, Sogang University, Seoul 121-742, Republic of Korea.
authors.forename: Jinsu
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Physics, Sogang University, Seoul 121-742, Republic of Korea.
authors.forename: Kyujoon
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Quantum Matter, ADSM, Hiroshima University, Higashi-Hiroshima 739-8530, Japan.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Takabatake
authors.affiliation: Department of Nano Physics, Sookmyung Women's University, Seoul 140-742, Republic of Korea.
authors.forename: Hanchul
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Nano Physics, Sookmyung Women's University, Seoul 140-742, Republic of Korea.
authors.forename: Miyoung
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Physics, Sogang University, Seoul 121-742, Republic of Korea.
authors.forename: Myung-Hwa
authors.initials: MH
authors.lastname: Jung