Effect of cobalt substitution on structural, impedance, ferroelectric and magnetic properties of multiferroic Bi2Fe4O9 ceramics

Mohapatra, Subrajeet; Sahu, Binod Bihari; Chandrasekhar, M.; Kumar, P.; Kaushik, S. D.; Rath, S.; Singh, Anil Kumar

doi:10.1016/j.ceramint.2016.05.008

Cited by 49 publications

(14 citation statements)

References 49 publications

(51 reference statements)

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“…Inspired by these works, Co species doping in the structure of BFO not only regarded as reactive sites for the photocatalysis process, but also facilitated the improvement of optical properties via electron transfer. It was assumed that cobalt (Co) element could be one promising element that doped into BFO as reported by other researches [24]. As cobalt element doping materials showed excellent electrochemical properties, the light absorption region of BFO could be extended and expected high photocatalytic activity.…”

Section: Introductionmentioning

confidence: 98%

Enhanced Activation of Persulfate by Co-Doped Bismuth Ferrite Nanocomposites for Degradation of Levofloxacin Under Visible Light Irradiation

et al. 2019

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In this study, magnetic visible light driven photocatalysts (bismuth ferrite, Bi2Fe4O9, BFO and Co-doped bismuth ferrite, Co-BFO) were successfully prepared by the facile hydrothermal method. The catalyst was used in the application of heterogeneous persulfate (PS) system under visible LED light irradiation for the degradation of levofloxacin (LFX), proving to be an excellent photocatalyst when evaluated by various characterization methods. The effect of Co-doping in the BFO structure was investigated that the decrease of band gap width and the generated photoelectrons and holes would effectively reduce the recombination of photogenerated electron-hole pairs, leading to the enhancement photocatalytic activity. The results demonstrated that Co-BFO catalyst had a high photodegradation efficiency over a wide pH range of 3.0–9.0 and the Co-BFO-2 composite displayed the optimal catalytic performance. It was found that the degradation rate of LFX by Co-BFO-2 catalyst was 3.52 times higher than that of pure BFO catalyst under visible light condition. The free radical trapping experiments and EPR tests demonstrated that superoxide, photogenerated holes and sulfate radicals were the main active species in the photocatalytic degradation of LFX. And a possible photocatalytic degradation mechanism of LFX was proposed in the Vis/Co-BFO/PS process. These findings provided new insight of the mechanism of heterogeneous activation of persulfate by Co-BFO under visible light irradiation.

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Section: Introductionmentioning

confidence: 98%

Enhanced Activation of Persulfate by Co-Doped Bismuth Ferrite Nanocomposites for Degradation of Levofloxacin Under Visible Light Irradiation

et al. 2019

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“…Complex impedance spectroscopy technique enables one to separate the real and imaginary parts of electrical parameters which provide a good insight into the role of grains, grain boundaries, and other interfaces on electrical conduction as a function of frequency and temperature which further enables one to establish correlations with defects and microstructural details. In past, impedance spectroscopy has extensively been used to study various doped oxide materials such as BaTiO 3 , SrTiO 3 , PZT, CaCu 3 Ti 4 O 12 , PLZT, BiFeO 3 and Bi 2 Fe 4 O 9 …”

Section: Resultsmentioning

confidence: 99%

“…In past, impedance spectroscopy has extensively been used to study various doped oxide materials such as BaTiO 3 , 48 SrTiO 3 , 49 PZT, 50 CaCu 3 Ti 4 O 12 , 51 , PLZT, 52 BiFeO 3 53 and Bi 2 Fe 4 O 9 . 54 Impedance spectroscopy is primarily based on the analysis of electrical impedance (Z), electrical modulus (M), permittivity (ε), and admittance (Y) of a material in complex plane as a function of frequency. These quantities are related to each other as follows:…”

Section: Impedance Spectroscopy Measurementsmentioning

confidence: 99%

Control of electrical leakage in magneto‐electric gallium ferrite via aliovalent substitution

et al. 2019

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One of the challenges with magnetoelectric multiferroic gallium ferrite (GaFeO3 or GFO) is its high electrical leakage whose control is essential for realizing any prospect of its practical applications. In this manuscript, we report on the effect of aliovalent doping at Fe site in magnetoelectric gallium ferrite in controlling its electrical leakage via tuning of its grain and grain‐boundary characteristics. Polycrystalline pure as well as zinc (Zn2+) and zirconium (Zr4+)‐doped gallium ferrite samples were synthesized by conventional solid‐state reaction method. Contrary to defect chemistry predictions, Zn2+ substituted samples show marked reduction in the electrical leakage with 10% Zn2+ substituted samples showing two orders of magnitude lower leakage current while Zr4+‐doped samples exhibit increased electrical leakage. This is supported by higher activation energy for conduction in the low frequency regime for Zn2+‐doped samples while nearly temperature independent conduction for Zr4+‐doped GFO samples. The results suggest that while Zn2+ doping leads to increase in resistance of the grain boundaries leading to lower conductivity, Zr4+ doping leads to opposite effect.

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“…Owing to a distribution of relaxation time, the semi‐circles exhibit a certain degree of contraction, and the centre of semi‐circle deviates from the horizontal axis of Z ′. These indicate the non‐Debye‐type relaxation mechanism occurs in BSBT–0.15BNT ceramic, and BSBT–0.15BNT ceramic contains essentially one electrical component around this temperature range [33, 34]. Fig.…”

Section: Resultsmentioning

confidence: 99%

High‐energy storage and temperature stable dielectrics properties of lead‐free BiScO ₃ –BaTiO ₃ – x (Bi _0.5 Na _0.5 )TiO ₃ ceramics

Xie

Liu

et al. 2018

IET Nanodielectrics

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Lead-free (1-x)(0.4BiScO 3-0.6BaTiO 3)-x(Bi 0.5 Na 0.5)TiO 3 (BSBT-xBNT) ceramics were prepared by traditional ceramics preparation method. The energy storage characteristics, as well as dielectric spectrum curves of BSBT-xBNT ceramics, were systematically used in research. The ternary system formed perovskite solid solution with dense and homogenous microstructure. BSBT-xBNT ceramics exhibited slimmer and slanted hysteresis loops followed by higher saturation polarisation (P max) and lower remnant polarisation (P r), which induced high-energy storage density of 1.39 J/cm 3 (E = 180 kV/cm). Ranging from 200 to 400°C, BSBT-xBNT ceramics had high permittivities, and a matching dielectric loss, which exhibited flat temperature coefficients of permittivity (TCɛ). The impedance spectroscopy analysis indicated that the non-Debye relaxation mechanism existed in BSBT-xBNT ceramics. BSBT-xBNT ceramics may have potential application value for the high-temperature capacitor.

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Effect of cobalt substitution on structural, impedance, ferroelectric and magnetic properties of multiferroic Bi2Fe4O9 ceramics

Cited by 49 publications

References 49 publications

Enhanced Activation of Persulfate by Co-Doped Bismuth Ferrite Nanocomposites for Degradation of Levofloxacin Under Visible Light Irradiation

Enhanced Activation of Persulfate by Co-Doped Bismuth Ferrite Nanocomposites for Degradation of Levofloxacin Under Visible Light Irradiation

Control of electrical leakage in magneto‐electric gallium ferrite via aliovalent substitution

High‐energy storage and temperature stable dielectrics properties of lead‐free BiScO ₃ –BaTiO ₃ – x (Bi _0.5 Na _0.5 )TiO ₃ ceramics

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Effect of cobalt substitution on structural, impedance, ferroelectric and magnetic properties of multiferroic Bi2Fe4O9 ceramics

Cited by 49 publications

References 49 publications

Enhanced Activation of Persulfate by Co-Doped Bismuth Ferrite Nanocomposites for Degradation of Levofloxacin Under Visible Light Irradiation

Enhanced Activation of Persulfate by Co-Doped Bismuth Ferrite Nanocomposites for Degradation of Levofloxacin Under Visible Light Irradiation

Control of electrical leakage in magneto‐electric gallium ferrite via aliovalent substitution

High‐energy storage and temperature stable dielectrics properties of lead‐free BiScO 3 –BaTiO 3 – x (Bi 0.5 Na 0.5 )TiO 3 ceramics

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Product

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High‐energy storage and temperature stable dielectrics properties of lead‐free BiScO ₃ –BaTiO ₃ – x (Bi _0.5 Na _0.5 )TiO ₃ ceramics