Synthesis of an Anticorrosive Pigment by Thermal Treatment of Iron Oxides from Steel Industry Wastes

This work reports the obtaining of an anticorrosive pigment composed mainly of hematite (ɑ-Fe2O3) from a powder steel industry waste from rust scale of rebar steel. This residue is mainly composed of Fe2O3 (87.97 %), SiO2 (6.13 %), CaO (1.88 %), Al2O3 (1.30%) and MnO (0.77 %). The total iron oxide of the residue is constituted by the following crystalline phases: magnetite, maghemita, lepidocrocita, wüstite, goethite and hematite. The production of a pigment with a high content of hematite was possible thanks to the high content of precursor iron oxides, which were calcined at different temperatures (750-850 °C) and holding times (0.5-1.50 h). For characterizing the iron content chemically and to identify their iron oxides phases, it was used X-ray fluorescence (XRF) and X-ray diffraction (XRD). The results showed that the pigment with the highest amount of hematite (ɑ-Fe2O3) was obtained at a calcination temperature of 850 °C and a holding time of 1.00 h.

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Discovery of Fe7O9: a new iron oxide with a complex monoclinic structure

Scientific Reports ◽

10.1038/srep32852 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 20

Author(s):

Ryosuke Sinmyo ◽

Elena Bykova ◽

Sergey V. Ovsyannikov ◽

Catherine McCammon ◽

Ilya Kupenko ◽

...

Keyword(s):

Applied Sciences ◽

Crystal Structure ◽

Iron Oxide ◽

Iron Oxides ◽

Industrial Applications ◽

Ambient Conditions ◽

X Ray Diffraction ◽

X Ray ◽

High Pressure High Temperature ◽

Insight Into

Abstract Iron oxides are fundamentally important compounds for basic and applied sciences as well as in numerous industrial applications. In this work we report the synthesis and investigation of a new binary iron oxide with the hitherto unknown stoichiometry of Fe7O9. This new oxide was synthesized at high-pressure high-temperature (HP-HT) conditions, and its black single crystals were successfully recovered at ambient conditions. By means of single crystal X-ray diffraction we determined that Fe7O9 adopts a monoclinic C2/m lattice with the most distorted crystal structure among the binary iron oxides known to date. The synthesis of Fe7O9 opens a new portal to exotic iron-rich (M,Fe)7O9 oxides with unusual stoichiometry and distorted crystal structures. Moreover, the crystal structure and phase relations of such new iron oxide groups may provide new insight into the cycling of volatiles in the Earth’s interior.

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The Influence of Synthesis Parameters on Structural and Magnetic Properties of Iron Oxide Nanomaterials

Nanomaterials ◽

10.3390/nano10010085 ◽

2020 ◽

Vol 10 (1) ◽

pp. 85 ◽

Cited By ~ 2

Author(s):

Laura Madalina Cursaru ◽

Roxana Mioara Piticescu ◽

Dumitru Valentin Dragut ◽

Ioan Albert Tudor ◽

Victor Kuncser ◽

...

Keyword(s):

Magnetic Properties ◽

Iron Oxide ◽

Iron Oxides ◽

Crystalline Phase ◽

Annealing Treatment ◽

Particle Size Analysis ◽

Size Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Order Of Magnitude

Magnetic iron oxides have been used in biomedical applications, such as contrast agents for magnetic resonance imaging, carriers for controlled drug delivery and immunoassays, or magnetic hyperthermia for the past 40 years. Our aim is to investigate the effect of pressure and temperature on the structural, thermal, and magnetic properties of iron oxides prepared by hydrothermal synthesis at temperatures of 100–200 °C and pressures of 20–1000 bar. It has been found that pressure influences the type of iron oxide crystalline phase. Thus, the results obtained by Mössbauer characterization are in excellent agreement with X-ray diffraction and optical microscopy characterization, showing that, for lower pressure values (<100 bar), hematite is formed, while, at pressures >100 bar, the major crystalline phase is goethite. In addition, thermal analysis results are consistent with particle size analysis by X-ray diffraction, confirming the crystallization of the synthesized iron oxides. One order of magnitude higher magnetization has been obtained for sample synthesized at 1000 bar. The same sample provides after annealing treatment, the highest amount of good quality magnetite leading to a magnetization at saturation of 30 emu/g and a coercive field of 1000 Oe at 10 K and 450 Oe at 300 K, convenient for various applications.

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Charge properties of red Argentine soils as an indicator of iron oxide/clay associations

Soil Research ◽

10.1071/sr98022 ◽

2001 ◽

Vol 39 (2) ◽

pp. 423 ◽

Cited By ~ 6

Author(s):

R. M. Torres Sánchez ◽

M. Okumura ◽

R. C. Mercader

Keyword(s):

Iron Oxide ◽

Iron Oxides ◽

Photoelectron Spectroscopy ◽

Electron Probe ◽

Surface Coverage ◽

Oxide Coating ◽

Point Of Zero Charge ◽

X Ray Diffraction ◽

X Ray ◽

North Eastern

The order of the relative degree of iron oxide coating of 4 samples of red soils from north-eastern Argentina was established using the point of zero charge (PZC), yielded by potentiometric titration, and the isoelectric point (IEP), obtained from the diffusion potential. When PZC is different from IEP, the relative fraction of apparent surface coverage could be assessed from the IEP. The results obtained by the application of X-ray diffraction, scanning electron microscopy, electron probe microanalysis, X-ray photoelectron spectroscopy, Mössbauer spectroscopy, and specif ic surface area, although essential to characterise the samples, did not allow us to determine the degree of iron oxide coating. Our findings show that the order of this degree is opposite to the order of the ratio of the amount of free iron oxides to that of clay in iron oxides/clay mixtures.

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Study of the Influence of Temperature on the Optical and Structural Properties of Dolomite

Applied Spectroscopy ◽

10.1177/0003702820934172 ◽

2020 ◽

Vol 74 (10) ◽

pp. 1280-1286

Author(s):

Lucas Train Loureço ◽

Celso de Araujo Duarte ◽

Dietmar William Foryta ◽

Bruno Guimarães Titon ◽

Eleonora Maria Gouvêa Vasconcellos

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Thermal Treatment ◽

X Ray Diffraction ◽

Electron Dispersive Spectroscopy ◽

Influence Of Temperature ◽

X Ray ◽

Different Temperatures ◽

Influence Of Temperature On ◽

Scanning Electron

The present work reports the results of structural and optical investigations in samples of natural dolomite, subjected to thermal treatment at different temperatures (500 ℃ to 700 ℃) and times (one up to three hours). The motivation is the evaluation of the changes that may occur in carbonaceous asteroids and meteorites, respectively, subjected to the action of the solar radiation and heated during the fall in the atmosphere. We carried out scanning electron microscopy, electron dispersive spectroscopy, X-ray diffraction, optical reflectance and photoluminescence measurements

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Iron oxide mineralogy of a hydrothermal assemblage on Santorini Island, Aegean Sea

Mineralogical Magazine ◽

10.1180/minmag.1982.046.338.14 ◽

1982 ◽

Vol 46 (338) ◽

pp. 89-93 ◽

Cited By ~ 8

Author(s):

Enver Murad

Keyword(s):

Mössbauer Spectroscopy ◽

Iron Oxide ◽

Iron Oxides ◽

Mossbauer Spectroscopy ◽

Aegean Sea ◽

Hydrothermal Fluids ◽

X Ray Diffraction ◽

X Ray ◽

Mößbauer Spectroscopy ◽

Basement Rocks

AbstractBasement rocks of Santorini have been locally impregnated by iron oxides and other minerals. The hydrothermal fluids which caused the mineralization have extensively altered the impregnated rocks, but left granditic garnets in these unaffected.Mössbauer spectroscopy and differential X-ray diffraction show that the iron oxides present are goethite and hematite in a ratio of about 2 : 1. The presence of hematite indicates that these minerals formed, directly from a hydrothermal phase, at higher temperatures than the recent submarine iron oxide deposits of Santorini, which contain no hematite.

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Microdomains in BaFeO3-y (0.35 < y < 0.50)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177039 ◽

1990 ◽

Vol 48 (4) ◽

pp. 780-781

Author(s):

M. Vallet-Regí ◽

M. Parras ◽

J.M. González-Calbet ◽

J.C. Grenier

Keyword(s):

Electron Diffraction ◽

Chemical Analysis ◽

Monoclinic Phase ◽

Orthorhombic Phase ◽

Total Iron ◽

Zone Axis ◽

Electron Micrograph ◽

X Ray Diffraction ◽

X Ray ◽

Compositional Variations

BaFeO3-y compositions (0.35<y<0.50) have been investigated by means of electron diffraction and microscopy to resolve contradictory results from powder X-ray diffraction data.The samples were obtained by annealing BaFeO2.56 for 48 h. in the temperature range from 980°C to 1050°C . Total iron and barium in the samples were determined using chemical analysis and gravimetric methods, respectively.In the BaFeO3-y system, according to the electron diffraction and microscopy results, the nonstoichiometry is accommodated in different ways as a function of the composition (y):In the domain between BaFeO2.5+δBaFeO2.54, compositional variations are accommodated through the formation of microdomains. Fig. la shows the ED pattern of the BaFeO2.52 material along thezone axis. The corresponding electron micrograph is seen in Fig. 1b. Several domains corresponding to the monoclinic BaFeO2.50 phase, intergrow with domains of the orthorhombic phase. According to that, the ED pattern of Fig. 1a, can be interpreted as formed by the superposition of three types of diffraction maxima : Very strong spots corresponding to a cubic perovskite, a set of maxima due to the superposition of three domains of the monoclinic phase along [100]m and a series of maxima corresponding to three domains corresponding to the orthorhombic phase along the [100]o.

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A Superhydrophobic, Antibacterial, and Durable Surface of Poplar Wood

Nanomaterials ◽

10.3390/nano11081885 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1885

Author(s):

Xinyu Wu ◽

Feng Yang ◽

Jian Gan ◽

Zhangqian Kong ◽

Yan Wu

Keyword(s):

Stearic Acid ◽

Antibacterial Properties ◽

Alkali Resistance ◽

Poplar Wood ◽

X Ray Diffraction ◽

X Ray ◽

Different Temperatures ◽

Acid And Alkali Resistance ◽

The Stability

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.

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Hydrothermal Ageing and Its Effect on Fracture Load of Zirconia Dental Implants

Materials ◽

10.3390/ma14113103 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3103

Author(s):

Laurent Gremillard ◽

Agnès Mattlet ◽

Alexandre Mathevon ◽

Damien Fabrègue ◽

Bruno Zberg ◽

...

Keyword(s):

Dental Implants ◽

Fracture Load ◽

Accelerated Ageing ◽

Dental Ceramics ◽

X Ray Diffraction ◽

X Ray ◽

Dental Restorations ◽

Different Temperatures ◽

Mechanical Performances ◽

Kinetics Of

Due to growing demand for metal-free dental restorations, dental ceramics, especially dental zirconia, represent an increasing share of the dental implants market. They may offer mechanical performances of the same range as titanium ones. However, their use is still restricted by a lack of confidence in their durability and, in particular, in their ability to resist hydrothermal ageing. In the present study, the ageing kinetics of commercial zirconia dental implants are characterized by X-ray diffraction after accelerated ageing in an autoclave at different temperatures, enabling their extrapolation to body temperature. Measurements of the fracture loads show no effect of hydrothermal ageing even after ageing treatments simulated a 90-year implantation.

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Modeling of magneto-conductivity of bismuth selenide: a topological insulator

SN Applied Sciences ◽

10.1007/s42452-021-04397-8 ◽

2021 ◽

Vol 3 (4) ◽

Author(s):

Yogesh Kumar ◽

Rabia Sultana ◽

Prince Sharma ◽

V. P. S. Awana

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Single Crystal ◽

Single Crystals ◽

X Ray Diffraction ◽

Field Range ◽

X Ray ◽

Bulk Carriers ◽

Different Temperatures

AbstractWe report the magneto-conductivity analysis of Bi2Se3 single crystal at different temperatures in a magnetic field range of ± 14 T. The single crystals are grown by the self-flux method and characterized through X-ray diffraction, Scanning Electron Microscopy, and Raman Spectroscopy. The single crystals show magnetoresistance (MR%) of around 380% at a magnetic field of 14 T and a temperature of 5 K. The Hikami–Larkin–Nagaoka (HLN) equation has been used to fit the magneto-conductivity (MC) data. However, the HLN fitted curve deviates at higher magnetic fields above 1 T, suggesting that the role of surface-driven conductivity suppresses with an increasing magnetic field. This article proposes a speculative model comprising of surface-driven HLN and added quantum diffusive and bulk carriers-driven classical terms. The model successfully explains the MC of the Bi2Se3 single crystal at various temperatures (5–200 K) and applied magnetic fields (up to 14 T).

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Direct Production of a Novel Iron-Based Nanocomposite from the Laser Pyrolysis ofFe(CO)5/MMAMixtures: Structural and Sensing Properties

Journal of Nanomaterials ◽

10.1155/2010/324532 ◽

2010 ◽

Vol 2010 ◽

pp. 1-12 ◽

Cited By ~ 4

Author(s):

R. Alexandrescu ◽

I. Morjan ◽

A. Tomescu ◽

C. E. Simion ◽

M. Scarisoreanu ◽

...

Keyword(s):

Iron Oxide ◽

Gas Sensors ◽

High Sensitivity ◽

X Ray Diffraction ◽

Direct Production ◽

X Ray ◽

Metallic Particles ◽

Ir Laser ◽

Iron Iron ◽

Optimum Working

Iron/iron oxide-based nanocomposites were prepared by IR laser sensitized pyrolysis ofFe(CO)5and methyl methacrylate (MMA) mixtures. The morphology of nanopowder analyzed by TEM indicated that mainly core-shell structures were obtained. X-ray diffraction techniques evidence the cores as formed mainly by iron/iron oxide crystalline phases. A partially degraded (carbonized) polymeric matrix is suggested for the coverage of the metallic particles. The nanocomposite structure at the variation of the laser density and of the MMA flow was studied. The new materials prepared as thick films were tested for their potential for acting as gas sensors. The temporal variation of the electrical resistance in presence ofNO2, CO, andCO2, in dry and humid air was recorded. Preliminary results show that the samples obtained at higher laser power density exhibit rather high sensitivity towardsNO2detection andNO2selectivity relatively to CO andCO2. An optimum working temperature of200°Cwas found.

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