Papers by Keyword: Iron Oxide

Abstract: Reduction of Fe₂O₃ by carbon monoxide (CO) have been studied by temperature programmed reduction (TPR) and X-ray diffraction spectroscopy (XRD). The influences of carbon monoxide concentration on the reducibility of iron oxides have been investigated. This study deals with the comparison in the reduction of Fe₂O₃ between 5% to 20% of CO concentration in the temperature range of 40–900 °C. The result shows that reducing behaviour of Fe₂O₃ is strongly dependent on the concentration of CO. It is suggested by using 20% of CO complete reduction takes place at lower temperature due to absence of intermediate FeO giving only two-steps reduction (Fe₂O₃ → Fe₃O₄ → metallic Fe). Moreover, excess of CO results the formation of iron carbide phase.

Abstract: This work is directed towards the synthesis of multifunctional nanoparticles of Fe₃O₄/Au nanocomposite, aimed at ensuring the magnetic and optical properties of magnetic-gold nanocomposite simultaneously. The nanoparticles showed good response to externally applied magnetic fields. The UV–vis spectroscopic examination reveals the maximum adsorption at ∼400 nm. Finally, the Fe₃O₄/Au nanoparticles were applied for detection mercury (II) ions in water solution.

Abstract: The resistive switching behavior of a low resistive p-type α-Fe₂O₃ thin film sandwiched between Fe bottom electrode and top electrodes of various materials (Fe, Ni and TiN) was studied by current-voltage measurements. When TiN was used for top electrode of memory cell, the reversible resistive switching behavior was observed for over 100 cycles. From impedance measurement, it was suggested that the resistive switching behavior in the TiN/p-type α-Fe₂O₃/Fe device is attributed to the change of the contact resistance in the interface between TiN and α-Fe₂O₃ layers.

Abstract: In this study, the potential of rust as a pigment in paint technology via sintering process was investigated. Iron (III) nitrate was the raw material used to make rust or iron oxide. The characteristics of iron oxide were analyzed. Moreover, iron oxide was mixed with other chemical components to make paint. The properties of paint in both liquid state and solid state were determined by portable field viscometer, pH indicator, glossmeter, pencil hardness test, and tape adhesive test. The optimum ratio of paint components for this study where used iron oxide as pigment. The other properties of pigments and paints will be conducted in the analysis study.

Abstract: Spinel magnetite Fe₃O₄ nanoparticles were synthesized using rambutan peel waste extract as a green ligation and chelating agent. The green synthesized nanoparticles were characterized employing X-ray diffraction (XRD), Raman spectroscopy, FTIR spectroscopy and transmission electron microscopy (TEM) studies. The XRD study revealed spinel phase hda a magnetite structure. The formation of iron oxide nanoparticles using rambutan extract was confirmed employing IR studies. XRD, FTIR and Raman spectrum analyses all supports the synthesis of Fe₃O₄ nanoparticles. The TEM revealed the spinel morphology of the biosynthesized nanoparticles with 200 nm.

Abstract: Composite powder of Fe/Fe₂O₃ type was synthesized by mechanical milling using commercially Fe and Fe₂O₃ powders in mass ratio of 35/65. The milling process leads to the powder homogenization, powder activation and formation of some Fe/Fe₂O₃ composite particles. The Fe/Fe₂O₃ composite powder obtained by mechanical milling and the un-milled Fe/Fe₂O₃ mixture were subjected to the reactive sintering procedure in argon atmosphere at 1100 °C for 6 hours. The sintering procedure promotes the reaction of the Fe with the Fe₂O₃ and the result is a sintered composite compact of Fe/Fe₃O₄/FeO type. The microstructure of the Fe/Fe₃O₄/FeO sintered composite compacts presents iron clusters in an oxide matrix. A more homogeneous iron clusters size and distribution in oxide matrix is observed in the case of the sintered compact obtained from mechano-activated powder. The X-ray diffraction (XRD), laser particles size analysis (LPSA), optical (OM) and scanning electron (SEM) microscopies techniques were used for the investigations.

Abstract: Electroreduction of Fe₂O₃ to Fe in sodium hydroxide solutions has been investigated. It is found that pure iron powder with uniform crystal particles can be obtained by electrolysis of Fe₂O₃ in alkaline solution. The porosity of the iron oxide (Fe₂O₃) pellet and the concentration of NaOH solution have significant influences on the electrolysis process. The deoxidation rate increases with increasing the concentration of NaOH solution, the grain size of iron products decreases with increasing the concentration of NaOH. The optimum NaOH concentration and pressure load used to fabricate Fe₂O₃ pellet are 60 wt% and 6 MPa, respectively. X-ray powder diffraction (XRD) analysis indicates that Fe₃O₄ was produced as the intermediate product during the electroreduction process.

Abstract: In order to investigate the possible effect of the scrap inclusions in recycling, microstructure and deformability of Zr-Nb based alloys cast with the addition of iron and iron oxide were studied. No visible iron oxide inclusions were observed in the arc-melted cake, suggesting that Zr and Fe₂O₃ reacted completely to dissociate Fe₂O₃ into Fe and O in the Zr. No oxide peaks were observed by XRD analyses. In Zr-Nb alloy melted with iron oxide, the oxygen content reached up to 3150 ppm. Zr-1.2 Nb alloys with high oxygen contents exhibited needle-shaped α phase. and the the thickness of needles decreased. In Zr-1.2Nb alloys with over 2000 ppm they are brittle and cracked during rolling process. In some region of the fracture surface brittle fracture feature such as vein-like pattern was observed. In the fractograph, no brittle second phase particles were observed. EDS spectra. It is apparent that Zr-Nb alloys with the addition of iron oxide during the handling of scrap materials exhibit the extremely brittle behavior.

Abstract: Abstract. Iron oxide particles with spherical, date-pit like, or polyhedron morphology were obtained by hydrothermal method. The morphology, thermal analysis, crystal structure of the products was characterized by FESEM, thermogravimetry (TG), X-ray diffraction (XRD), respectively. The measured results reveal that the product of three different shapes is hematite (α-Fe₂O₃).

Abstract: The impact of heat treatment temperature on the electrochemical performance of Fe₃O₄-activated carbon nanocomposite electrodes was investigated using constant current charge-discharge and Electrochemical Impedance Spectroscopy (EIS). An improved capacitive behaviour was observed due to the effect of enhanced ionic and electronic conductivities of the 4 wt% Fe₃O₄/AC by thermally heating at 200 °C for 6 hours. It was found that the internal resistance of 4 wt% Fe₃O₄/AC composite electrode calcined at 200 °C for 6 hours is the smallest (2.97 Ω) in comparison to those untreated (4.36 Ω) composite electrodes. The ion mobility inside the porous composite electrodes is favourable at 200 °C, accompanying with the enhanced electronic conductivity of oxide electrode as a result of improved crystallinity. The EIS results and analysis not only have significant impact on the fundamental understanding of the temperature-dependent structural and electrochemical properties of electrode but also provide the insights on the diffusion mechanism of the nanocomposite in neutral Na₂SO₃ electrolyte.