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

Journal Article · Tue Jan 14 04:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4861151· OSTI ID:22271277

Kurni, O.; Alam, M. S. ^[1]; Sinha, B. L. ^[2]; Ahmmad, Bashir ^[3]

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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)

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 spiral 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.

• OSTI ID: 22271277
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 2 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

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