title: Origin of colossal dielectric permittivity of rutile Ti₀.₉In₀.₀₅Nb₀.₀₅O₂: single crystal and polycrystalline.
abstract: In this paper, we investigated the dielectric properties of (In + Nb) co-doped rutile TiO2 single crystal and polycrystalline ceramics. Both of them showed colossal, up to 10(4), dielectric permittivity at room temperature. The single crystal sample showed one dielectric relaxation process with a large dielectric loss. The voltage-dependence of dielectric permittivity and the impedance spectrum suggest that the high dielectric permittivity of single crystal originated from the surface barrier layer capacitor (SBLC). The impedance spectroscopy at different temperature confirmed that the (In + Nb) co-doped rutile TiO2 polycrystalline ceramic had semiconductor grains and insulating grain boundaries, and that the activation energies were calculated to be 0.052 eV and 0.35 eV for grain and grain boundary, respectively. The dielectric behavior and impedance spectrum of the polycrystalline ceramic sample indicated that the internal barrier layer capacitor (IBLC) mode made a major contribution to the high ceramic dielectric permittivity, instead of the electron-pinned defect-dipoles.
authors: Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
authors: Yongli
authors: Y
authors: Song
authors: Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
authors: Xianjie
authors: X
authors: Wang
authors: Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
authors: Yu
authors: Y
authors: Sui
authors: Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
authors: Ziyi
authors: Z
authors: Liu
authors: Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
authors: Yu
authors: Y
authors: Zhang
authors: Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
authors: Hongsheng
authors: H
authors: Zhan
authors: Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
authors: Bingqian
authors: B
authors: Song
authors: Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
authors: Zhiguo
authors: Z
authors: Liu
authors: Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
authors: Zhe
authors: Z
authors: Lv
authors: Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
authors: Lei
authors: L
authors: Tao
authors: Department of Physics &Astronomy, University of Wyoming, Laramie, WY 82071, USA.
authors: Jinke
authors: J
authors: Tang