New insights about the formation of copper ferrite: in situ X-ray diffraction study

Hegazy, Eman Z.; elmaksod, islam H. Abd; Ibrahim, Amal M.; El-Shafay, Shaymaa El-Sayed

doi:10.1186/s42269-018-0010-9

Cited by 8 publications

(3 citation statements)

References 11 publications

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“…We note the presence of Zn in the analyzed spinel. Pure cuprospinel was also obtained by reactions between magnetite and liquid Cu(OH) 2 where Fe 2+ was completely replaced by Cu 2+ at high temperature (1000 • C) after two hours [9].…”

Section: Introductionmentioning

confidence: 99%

Copper-Bearing Magnetite and Delafossite in Copper Smelter Slags

Gezzaz,

Ciobanu,

Cook

et al. 2023

Minerals

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The cooling paths and kinetics in the system Cu-Fe-O are investigated by the empirical micro- and nanoscale analysis of slags from the flash furnace smelter at Olympic Dam, South Australia. We aim to constrain the exsolution mechanism of delafossite (Cu1+Fe3+O2) from a spinel solid solution (magnetite, Fe3O4) and understand why cuprospinel (CuFe2O4) is never observed, even though, as a species isostructural with magnetite, it might be expected to form. Flash furnace slags produced in the direct-to-blister copper smelter at Olympic Dam contain four Cu-bearing phases: Cu-bearing magnetite, delafossite, metallic copper, and cuprite. Delafossite coexists with magnetite as rims and lamellar exsolutions, as well as bladed aggregates, associated with cuprite within Si-rich glass. The empirical compositions of magnetite and rim delafossite are (Fe2+6.89Cu2+0.86Co0.13Mg0.15Si0.02)8.05 (Fe3+15.52Al0.41Ti0.01Cr0.01)15.95O32, and (Cu1+0.993Co0.002Mg0.002)0.997(Fe3+0.957Al0.027Ti0.005Si0.004)0.993O2, respectively. The measured Cu content of magnetite represents a combination of a solid solution (~6 mol.% cuprospinel endmember) and exsolved delafossite lamellae. Atomic-resolution high-angle annular dark field scanning transmission electron microscope (HAADF STEM) imaging shows epitaxial relationships between delafossite lamellae and host magnetite. Defects promoting the formation of copper nanoparticles towards the lamellae margins suggest rapid kinetics. Dynamic crystallization under locally induced stress in a supercooled system (glass) is recognized from misorientation lamellae in delafossite formed outside magnetite grains. The observations are concordant with crystallization during the cooling of molten slag from 1300 °C to <1080 °C. Melt separation through an immiscibility gap below the solvus in the system Cu-Fe-O is invoked to form the two distinct delafossite associations: (i) melt-1 from which magnetite + delafossite form; and (ii) melt-2 from which delafossite + cuprite form. Such a path also corroborates the published data explaining the lack of cuprospinel as a discrete phase in the slag. Delafossite rims form on magnetite at a peritectic temperature of ~1150 °C via a reaction between the magnetite and copper incorporated in the oxide/Si-rich melt. The confirmation of such a reaction is supported by the observed misfit orientation (~10°) between the rim delafossite and magnetite. HAADF STEM imaging represents a hitherto underutilized tool for understanding pyrometallurgical processes, and offers a direct visualization of phase relationships at the smallest scale that can complement both experimental approaches and theoretical studies based on thermodynamic modelling.

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Section: Introductionmentioning

confidence: 99%

Copper-Bearing Magnetite and Delafossite in Copper Smelter Slags

Gezzaz,

Ciobanu,

Cook

et al. 2023

Minerals

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“…Hence ferrite plays an essential role in a variety of technical fields such as electronic devices, communication systems and medical technology. Among that promising applications, ferrite has been used as shielding material for reducing electrical noises, antenna for receiving signals and in wireless communications [4][5][6][7].The copper/iron/oxygen system (copper ferrites) has achieved more interest due to ease of separation, low cost, unique structural, electrical and magnetic properties and mostly the applications as a magnetic material in diverse fields like data storage, gas sensors, magnetic resonance imagining and drug delivery system [8]. Copper ferrite occurs naturally in two crystallographic spinel structures: the high-temperature cubic phase (c-CuFe2O4), and the low-temperature tetragonal phase (t-CuFe2O4).…”

Section: Introductionmentioning

confidence: 99%

Analysis of DC Conductivity and I-V Characterization of Nanocrystalline Copper Ferrite Sample at and above Room Temperature

Mandal

2023

MSF

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Spinel copper ferrite nanoparticles have wide spread technological applications. Polycrystalline copper ferrite nanoparticles is prepared by sonochemical method. The structural property is investigated by X-ray diffraction study, which reveals cubic spinel structure of copper ferrite NPs with average crystalline size of 20 nm. The temperature variation of DC conductivity of copper ferrite nanoparticles is studied. The conductivity is observed to increase with temperature which implies semiconducting nature of copper ferrite. The Mott study reveals that conduction process is three dimensional in present case. Again, p-n junction formation in the ferrite system is observed from the current voltage (I-V) study. This study further shows that the trap height increases with temperature. Ideality factor with values greater than 1 has been observed in present case.

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“…Magnetic nanoparticles have attracted much interest in biomedicine because of their beneficial magnetic, optical, and antibacterial properties (Gheidari et al, 2020). Spinel ferrites with remarkable electrical and magnetic properties and outstanding chemical stability received much attention (Hegazy et al, 2018). Based on these properties, a variety of applications have been reported, including medical (Amiri et al, 2019b;Predoi et al, 2019), immunoassay (Wu et al, 2020), electronic devices (Qindeel et al, 2021), adsorption (Predoi et al, 2020), and catalysis (Amiri et al, 2019a).…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Antimicrobial Activities of CuxFe3-xO4/PANI Nanocomposites

Eid

El‐Helaly

El-Sheikh

et al. 2022

Egypt. J. Microbiol.

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M AGNETIC nanocomposites loaded with antimicrobial drugs have grown in popularity for treating infectious diseases due to their magnetic properties and the ability to penetrate bacteria cells. In this research, Cu x Fe 3-x O 4 nanoparticles and Cu x Fe 3-x O 4 /PANI nanocomposites were synthesized, characterized, and examined for their antimicrobial activity. The in-situ oxidative polymerization of aniline in the presence of Cu x Fe 3-x O 4 nanoparticles produced Cu x Fe 3-x O 4 /PANI nanocomposites with distinct spinel ferrites. XRD, FT-IR, VSM, SEM, EDX, TEM, and XPS techniques confirmed the successful synthesis of the Cu x Fe 3-x O 4 /PANI nanocomposites. The analysis of magnetization patterns of Cu x Fe 3-x O 4 /PANI nanocomposites revealed their superparamagnetic characteristics. With increasing Cu 2+ ratios, both the pure copper ferrites nanoparticles and the Cu x Fe 3-x O 4 /PANI nanocomposites exhibited enhanced antimicrobial effects against gram-positive (Staph), gram-negative (E. coli, P. aeruginosa, and K. pneumoniae), and fungi such as (C. albicans), which is consistent with decreasing the order of crystal size (nm) and the lattice strain, where crystal size and lattice strain decreased with increasing Cu 2+ ratio. SEM micrographs revealed changes in bacterial shape, deformation of fungal cell walls, and bacterial and yeast colonies collapsing. Furthermore, the nanocomposites are more effective against gram-negative bacteria and Candida albicans than gram-positive bacteria, displaying the alteration of bacterial shape, fungal cell wall deformation, and collapsing bacterial and yeast colonies. The results presented an approach for using Cu x Fe 3-x O 4 and Cu x Fe 3-x O 4 /PANI as an alternative promising antimicrobial agent against several multidrugresistant microbes.

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New insights about the formation of copper ferrite: in situ X-ray diffraction study

Cited by 8 publications

References 11 publications

Copper-Bearing Magnetite and Delafossite in Copper Smelter Slags

Copper-Bearing Magnetite and Delafossite in Copper Smelter Slags

Analysis of DC Conductivity and I-V Characterization of Nanocrystalline Copper Ferrite Sample at and above Room Temperature

Synthesis, Characterization, and Antimicrobial Activities of CuxFe3-xO4/PANI Nanocomposites

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