Nanoparticles of FeNbO4 Produced by Microwave Assisted Combustion Reaction: A Potential Technology for the Treatment of Wastewater

Andrade, Fabrício Vieira de; Costa, Cynthia Ferreira; Freitas, Márcio Roberto de; Cabral, Ana Cristina Tolentino; Barros, N. M.; Lima, Geraldo Μ. de

doi:10.1590/1980-5373-mr-2020-0166

Cited by 2 publications

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“…The family of ceramic materials with ABO 4 -type structures have been investigated since the last century due to their promising applications, such as photodetector system, solar energy conversion, gas sensor, photocatalyst, and electrode material for Li-ion batteries, etc. [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. In this context, the compound belonging to this rutile-type ABO 4 family, called iron antimonate FeSbO 4 , has been the subject of several researchers because it is a potential candidate for several applications, such as gas detector sensors and catalysis properties.…”

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confidence: 99%

Investigating the Correlation between the Microstructure and Electrical Properties of FeSbO4 Ceramics

et al. 2022

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FeSbO4 powder was prepared using the solid-state reaction method in this work. Afterward, the dense and porous ceramics were obtained by sintering the pressed powder calcined at temperatures of 900 and 1000 °C for 4 h. Rietveld profile analysis of the X-ray powder diffraction data showed that FeSbO4 adopts the trirutile-type structure (space group P42/mnm, with a ≅ 4.63 Å and c ≅ 9.23 Å). SEM images showed that the powder calcined at 900 °C after being sintered at 1200 °C resulted in ceramics of higher crystallinity, larger grains, and consequently, low porosity. The dielectric properties were measured in the frequency range of 10−1 Hz–1 MHz as a function of temperature (25–250 °C). The real (σ′) and imaginary (σ″) parts of the complex conductivity increase with rising annealing temperature for both samples. The real conductivity in the AC region for 𝑓 = 100 kHz was 1.59×10−6 S·cm−1 and 7.04×10−7 S·cm−1 for the ceramic samples obtained from the powder calcined at 900 (C-900) and 1000 °C (C-1000), respectively. Furthermore, the dielectric constants (k′) measured at room temperature and f=100 kHz were 13.77 (C-900) and 6.27 (C-1000), while the activation energies of the grain region were Ea = 0.53 eV and Ea = 0.49 eV, respectively. Similar activation energy (Ea = 0.52 eV and 0.49 eV) was also obtained by the brick-layer model and confirmed by the adjustment of activation energy by DC measurements which indicated an absence of the porosity influence on the parameter. Additionally, loss factor values were obtained to be equal to 3.8 (C-900) and 5.99 (C-1000) for measurements performed at 100 Hz, suggesting a contribution of the conductivity originated from the combination or accommodation of the pores in the grain boundary region. Our results prove that the microstructural factors that play a critical role in the electrical and dielectric properties are the average grain size and the porosity interspersed with the grain boundary region.

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