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Title: Room temperature dielectric and magnetic properties of Gd and Ti co-doped BiFeO{sub 3} ceramics

Room temperature dielectric and magnetic properties of BiFeO{sub 3} samples, co-doped with magnetic Gd and non-magnetic Ti in place of Bi and Fe, respectively, were reported. The nominal compositions of Bi{sub 0.9}Gd{sub 0.1}Fe{sub 1–x}Ti{sub x}O{sub 3} (x = 0.00-0.25) ceramics were synthesized by conventional solid state reaction technique. X-ray diffraction patterns revealed that the substitution of Fe by Ti induces a phase transition from rhombohedral to orthorhombic at x > 0.20. Morphological studies demonstrated that the average grain size was reduced from ∼1.5 μm to ∼200 nm with the increase in Ti content. Due to Ti substitution, the dielectric constant was stable over a wide range of high frequencies (30 kHz to 20 MHz) by suppressing the dispersion at low frequencies. The dielectric properties of the compounds are associated with their improved morphologies and reduced leakage current densities probably due to the lower concentration of oxygen vacancies in the compositions. Magnetic properties of Bi{sub 0.9}Gd{sub 0.1}Fe{sub 1–x}Ti{sub x}O{sub 3} (x = 0.00-0.25) ceramics measured at room temperature were enhanced with Ti substitution up to 20% compared to that of pure BiFeO{sub 3} and Ti undoped Bi{sub 0.9}Gd{sub 0.1}FeO{sub 3} samples. The enhanced magnetic properties might be attributed to the substitution induced suppression of spiralmore » spin structure of BiFeO{sub 3}. An asymmetric shifts both in the field and magnetization axes of magnetization versus magnetic field curves was observed. This indicates the presence of exchange bias effect in these compounds notably at room temperature.« less
Authors:
; ;  [1] ;  [2] ;  [3]
  1. Department of Physics, Bangladesh University of Engineering and Technology, Dhaka (Bangladesh)
  2. Atomic Energy Center, Dhaka (Bangladesh)
  3. Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510 (Japan)
Publication Date:
OSTI Identifier:
22271277
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BISMUTH COMPOUNDS; CONCENTRATION RATIO; DIELECTRIC MATERIALS; DOPED MATERIALS; FERRITES; GADOLINIUM COMPOUNDS; GRAIN SIZE; MAGNETIC PROPERTIES; MAGNETIZATION; ORTHORHOMBIC LATTICES; PERMITTIVITY; PHASE TRANSFORMATIONS; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; TITANIUM COMPOUNDS; TRIGONAL LATTICES; VACANCIES; X-RAY DIFFRACTION