title: Characterization of magnetic and dielectric properties of Bi(1-x)Gd(x)FeO3 nanoparticles by local structure analyses.
abstract: Bi(1-x)Gd(x)FeO3 (0 < or = x < or = 1.0) nanoparticles were synthesized by a wet chemical method. The annealing temperatures were controlled to obtain single-phase Bi(1-x)Gd(x)FeO3 nanoparticles. The crystal diameters decreased as the number of doped Gd ions increased. The crystal structure changed, as the number of Gd ions increased, from rhombohedral to orthorhombic perovskite, at x = 0.2. The behavior of the magnetization curves observed at various values of x (x = 0.05, 0.1, 0.15) of the rhombohedral structure suggested that the canted antiferromagnetism and remanent magnetization (M(r)) drastically increased, compared with those at x = 0 (BiFeO3). It is suggested that the spin-canting angle of the Fe ions increased with the increase in the number of Gd ions. The dielectric properties at x = 0.1 showed that the dielectric loss (tan delta) was improved, compared with that at x = 0 (BiFeO3), by approximately 90%, while the real part of the dielectric constant epsilon' was reduced by approximately 15%. The reason is that the doping impurities restrained the reduction in the leakage current. It was found, from the X-ray absorption fine structure (XAFS) spectra, that Gd ions were doped accurately and that the symmetry of the B site was improved. The Mössbauer analysis suggested the existence of magnetic cycloid spiral ordering.
authors.forename: Takuya
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authors.lastname: Yanoh
authors.forename: Akinobu
authors.initials: A
authors.lastname: Kurokawa
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Shinya
authors.initials: S
authors.lastname: Yano
authors.forename: Kazuki
authors.initials: K
authors.lastname: Onuma
authors.forename: Takaya
authors.initials: T
authors.lastname: Kondo
authors.forename: Kazunari
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authors.lastname: Miike
authors.forename: Toshiki
authors.initials: T
authors.lastname: Miyasaka
authors.forename: Ko
authors.initials: K
authors.lastname: Mibu
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ichiyanagi