Dielectric properties, complex impedance and electrical conductivity of Fe2TiO5 nanopowder compacts and bulk samples at elevated temperatures

Nikolić, Maria Vesna; Sekulić, Dalibor L.; Vasiljević, Zorka Ž.; Luković, Miloljub D.; Pavlović, Vladimir B.; Aleksić, O.S.

doi:10.1007/s10854-016-6125-6

Cited by 20 publications

(30 citation statements)

References 30 publications

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“…This was attributed to the polaron hopping type conductivity mechanism which was confirmed by AC conductivity analysis. Nikolic et al reported changes in electrical conductivity in accordance with Jonscher's power law for nanopowder and bulk samples [130]. They also concluded that the quantum mechanical-tunneling model for the case of small polaron hopping can be applied at higher temperatures which outlines the conductivity in Fe 2 TiO 5 .…”

Section: Fe 2 Tio 5 As a Photoanode Materialsmentioning

confidence: 84%

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Recent progress in iron oxide based photoanodes for solar water splitting

Gurudayal

Bassi

Sritharan

et al. 2018

J. Phys. D: Appl. Phys.

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Solar assisted water splitting in a PEC is an attractive concept to store solar energy as hydrogen fuel but the effective efficiency of the process is too low for it to be a serious contender for commercialization. The most important component of the PEC to achieve efficient water splitting is a photo active anode that could effectively absorb photons and deliver holes for the oxygen evolution reaction. Hematite has many attributes that make it a good candidate material for a photoanode but it also has some deficiencies. This article reviews the state-of-the-art hematite-based photoanodes, with special emphasis on attempts made by researchers to overcome its drawbacks. The numerous research reports are categorized under distinct strategies such as nanostructuring, elemental doping, surface passivation, cocatalyst application, conducting template incorporation and heterostructures which are possible pathways to improve the performance of hematite. The scientific understandings of the operating mechanisms for each strategy are systematically presented and discussed, and the improvements achieved by different approaches are compared. Some cutting-edge strategies, such as heterojunctions, could be important and hematite based heterostructures are discussed. A developing interest in an emerging material, Fe 2 TiO 5 is also discussed and some of the important benefits of this material are presented. Finally, the importance of scaling up the technology is discussed and attention is drawn to some possible challenges on scaling up. The paper concludes with some future technology directions and prospects for hematite-based photoanodes.

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Section: Fe 2 Tio 5 As a Photoanode Materialsmentioning

confidence: 84%

“…There have been reports on the dielectric properties and electrical conductivity of Fe 2 TiO 5 bulk samples [130][131][132]. Sharma et al investigated the complex dielectric and impedance properties of Fe 2 TiO 5 and reported that its non-Debye type dielectric relaxation follows a thermally activated process [131].…”

Section: Fe 2 Tio 5 As a Photoanode Materialsmentioning

confidence: 99%

Recent progress in iron oxide based photoanodes for solar water splitting

Gurudayal

Bassi

Sritharan

et al. 2018

J. Phys. D: Appl. Phys.

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“…Highly conducting grains and the resistive nature of grain boundaries present in nickel manganite contribute to this relaxation process [ 57 ]. One semicircle shows that either one relaxation process (originating from grains or grain boundaries) is dominant, or grain and grain boundary contributions overlap [ 58 , 59 ]. Adsorption of water molecules by a surface reaction mechanism with the nanocrystalline fiber particles of NiMn 2 O 4 with a rise in RH leads to an increase in ionic conductivity in accordance with the humidity sensing mechanism [ 35 , 60 ].…”

Section: Resultsmentioning

confidence: 99%

“…The capacitance was calculated taking into account the case of parallel resistance and CPE element, as described in detail in [ 58 ]. The determined capacitance increased slightly with an increase in RH in a similar range for both working temperatures.…”

Section: Resultsmentioning

confidence: 99%

Electrospun Nickel Manganite (NiMn2O4) Nanocrystalline Fibers for Humidity and Temperature Sensing

Dojčinović

Vasiljević

Krstić

et al. 2021

Sensors

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Nickel manganite nanocrystalline fibers were obtained by electrospinning and subsequent calcination at 400 °C. As-spun fibers were characterized by TG/DTA, Scanning Electron Microscopy and FT-IR spectroscopy analysis. X-ray diffraction and FT-IR spectroscopy analysis confirmed the formation of nickel manganite with a cubic spinel structure, while N2 physisorption at 77 K enabled determination of the BET specific surface area as 25.3 m2/g and (BJH) mesopore volume as 21.5 m2/g. The material constant (B) of the nanocrystalline nickel manganite fibers applied by drop-casting on test interdigitated electrodes on alumina substrate, dried at room temperature, was determined as 4379 K in the 20–50 °C temperature range and a temperature sensitivity of −4.95%/K at room temperature (25 °C). The change of impedance with relative humidity was monitored at 25 and 50 °C for a relative humidity (RH) change of 40 to 90% in the 42 Hzπ1 MHz frequency range. At 100 Hz and 25 °C, the sensitivity of 327.36 ± 80.12 kΩ/%RH was determined, showing that nickel manganite obtained by electrospinning has potential as a multifunctional material for combined humidity and temperature sensing.

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“…The CPE element was used to replace a capacitor in order to compensate for the depressed semicircle as described in detail in Ref. . Good agreement between measured and analyzed spectra was obtained as shown in the example presented on insets in Figure , with an average error of about 2%.…”

Section: Resultsmentioning

confidence: 99%

Investigation of ZnFe₂O₄ spinel ferrite nanocrystalline screen‐printed thick films for application in humidity sensing

Nikolić

Vasiljević

Luković

et al. 2019

Int J Applied Ceramic Tech

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Zinc ferrite nanocrystalline powder was obtained by solid state synthesis of starting zinc oxide and hematite nanopowders. Field emission scanning electron microscopy and transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy and Raman spectroscopy confirmed the formation of nanocrystalline zinc‐ferrite powder with a mixed spinel structure with small amounts of remaining zinc oxide and hematite as impurities. Thick film paste was formed and screen printed on test interdigitated PdAg electrodes on alumina substrate. Formation of a porous nanocrystalline structure was confirmed by scanning electron microscopy and Hg porosimetry. Humidity sensing properties of zinc ferrite thick films were investigated by monitoring the change in impedance in the relative humidity interval 30%‐90% in the frequency range 42 Hz‐1 MHz at room temperature (25°C) and 50°C. At 42 Hz at both analyzed temperatures the impedance reduced ~46 times in the humidity range 30%‐90%. The dominant influence of grain boundaries was confirmed by analysis of complex impedance with an equivalent circuit.

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Dielectric properties, complex impedance and electrical conductivity of Fe2TiO5 nanopowder compacts and bulk samples at elevated temperatures

Cited by 20 publications

References 30 publications

Recent progress in iron oxide based photoanodes for solar water splitting

Recent progress in iron oxide based photoanodes for solar water splitting

Electrospun Nickel Manganite (NiMn2O4) Nanocrystalline Fibers for Humidity and Temperature Sensing

Investigation of ZnFe₂O₄ spinel ferrite nanocrystalline screen‐printed thick films for application in humidity sensing

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Dielectric properties, complex impedance and electrical conductivity of Fe2TiO5 nanopowder compacts and bulk samples at elevated temperatures

Cited by 20 publications

References 30 publications

Recent progress in iron oxide based photoanodes for solar water splitting

Recent progress in iron oxide based photoanodes for solar water splitting

Electrospun Nickel Manganite (NiMn2O4) Nanocrystalline Fibers for Humidity and Temperature Sensing

Investigation of ZnFe2O4 spinel ferrite nanocrystalline screen‐printed thick films for application in humidity sensing

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Investigation of ZnFe₂O₄ spinel ferrite nanocrystalline screen‐printed thick films for application in humidity sensing