Luminescence, structure and insight on the inversion degree from normal to inverse spinel in a ZnAl(2−)Fe3+O4 system

Ogugua, Simon N.; Ntwaeaborwa, O.M.; Swart, H.C.

doi:10.1016/j.bsecv.2020.02.005

Cited by 27 publications

(5 citation statements)

References 73 publications

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“…All B1s spectra obtained have shown peaks centred at ~193.3 eV (Figure 3g), attributable to B-O [20]. For more intensive spectra obtained at surfaces boronized at 900-950 • C, a peak centred at ~187.8 eV was observed, as well as a minor peak at ~190.6 eV (Figure 3h), which, based on the results reported earlier [19], may be assigned to B-O-Al bonds. The peak at 187.8 eV here should most likely be attributed to elemental boron from amorphous boron residues on the surface.…”

Section: Characterisation Of the Alumina Surface By Sem Eds Xps And X...supporting

confidence: 65%

“…Respectively, the appearance of this peak might be attributed to borate units bound to aluminium (Al-O-B). In their study, Ogugua et al [19] investigated an iron-doped ZnAl 2 O 4 system and determined Al2p peak's shift to higher binding energies with the increase of iron concentration. The authors assigned the appearance of Al2p peak components at 76.0 eV and 76.1 eV to Al-O-Fe.…”

Section: Characterisation Of the Alumina Surface By Sem Eds Xps And X...mentioning

confidence: 99%

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Effect of Thermochemical Boronizing of Alumina Surface on the Borate Crystals Growth and Interaction with Nickel and Nickel Alloy

Škamat

Lebedev²,

Černašėjus³

et al. 2022

Crystals

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Wettability at the metal-ceramic interface is highly important for the development of modern composite materials. Poor wettability by metal melts restricts the use of alumina in protective metal matrix composite (MMC) coatings. In the present experimental study, the possibility to modify wetting properties of alumina by thermochemical surface boronizing was investigated. The results of SEM, EDS, XRD and XPS characterisation of surfaces revealed the formation of oxygen containing Al–B compounds identified as aluminium borates (Al18B4O33/Al4B2O9); no signs of non-oxide Al–B compounds were observed. The shape of the single splats deposited on the boronized alumina surface by the thermal spray and re-melted in the furnace revealed that significant wetting improvement by self-fluxing nickel alloy did not occur. However, the improvement of adhesion between the nickel/nickel alloy and Al2O3 surface was obtained due to formation of an intermediate layer consisting of B, O, Al and Si between the metal and ceramic surfaces at the presence of some silicon at the modified surfaces. The presented study demonstrates that the thermochemical boronizing of alumina in amorphous boron medium is a simple method to obtain a thin aluminium borate layer consisting of oriented nano-rod-like crystals, whose growing direction is predetermined by the orientation of the alumina grains’ faces at surface.

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Section: Characterisation Of the Alumina Surface By Sem Eds Xps And X...supporting

confidence: 65%

Section: Characterisation Of the Alumina Surface By Sem Eds Xps And X...mentioning

confidence: 99%

Effect of Thermochemical Boronizing of Alumina Surface on the Borate Crystals Growth and Interaction with Nickel and Nickel Alloy

Škamat

Lebedev²,

Černašėjus³

et al. 2022

Crystals

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“…As announced in the study of Zhou et al [111], the surface of Cr was found to be rich in Cr 6+ ions, which only appear at the surface. Finally, the Al-2p spectra exhibit two dominant peaks at 74.11 and 75.76 eV, corresponding to the distribution of Al 3+ ions at the O h and T d sites due to M-O and M-OH, respectively [112,113]. These results revealed the mixed spinel structure of the prepared samples, due to the cation distribution at both O h and T d sites [114].…”

Section: Xps Studymentioning

confidence: 79%

Fabrication, characterization, and antibacterial activity of ferrite, chromite, and aluminate nanoparticles

El Hajjar,

Bitar,

Zahr

et al. 2024

Mater. Res. Express

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Zn0.33Co0.33Mg0.33X2O4 nanoparticles (NPs), where X = Fe, Cr, Al and denoted by F, C, and A, were prepared by the co-precipitation method. X-ray diffraction patterns validated the formation of NPs with cubic spinel structure with the detection of small amounts of impurities in samples C (Cr2O3) and A (MgO). Transmission electron micrographs showed a nearly spherical shape for samples F and A. However, sample C revealed cubic and nearly spherical shapes. Energy-dispersive x-ray analysis ensured the presence of chemical constituents in all samples. The vibrational modes of NPs were confirmed with Fourier transform infrared spectroscopy. The direct bandgap energy values, calculated using ultraviolet-visible spectroscopy, were in the range of 2.355 and 2.967 eV for F, C, and A samples. X-ray photoelectron spectroscopy analysis confirmed the compositions as well as the valence states of all elements. Magnetic hysteresis (M–H) loops revealed a soft ferromagnetic behavior. Sample F exhibited a higher saturation magnetization, remanent magnetization, magnetic moment, and magnetic anisotropy compared to those of samples C and A. The antibacterial activity of the tested samples against four bacteria (Staphylococcus aureus, Stenotrophomonas maltophilia, Escherichia coli, and Enterococcus faecium) was determined using the broth microdilution assay, minimum bactericidal concentration (MBC), and time-kill test. The prepared NPs exhibited varying antibacterial activity due to multiple factors. These results highlighted the potential utility of the ternary ferrite, chromite, and aluminate NPs in the treatment of microbial infections, particularly multidrug-resistant bacteria.

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“…For example, the decay time of the d-d luminescence of Ti-doped Al 2 O 3 is 3.2 µs, (43) whereas that of our sample is approximately 8.0 ms. The origin of the emission at ~790 nm could be explained by the 4 T 1 -6 A 1 transition of Fe 3+ ions, (55)(56)(57)(58) which was an unexpected contaminant.…”

Section: Resultsmentioning

confidence: 99%

Photoluminescence and Radioluminescence Properties of Y3Al5O12 Doped with 3d-Transition Metal Ions

Kawaguchi,

Hayashi,

Kunikata

et al. 2024

Sensors and Materials

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The photoluminescence and radioluminescence properties of Y 3 (Al 0.99 TM 0.01 ) 5 O 12 (TM = Ti, V, Mn, and Cu) single crystals were investigated. Single crystalline rods of approximately 5 mm diameter were grown by the optical floating zone method. The photoluminescence quantum yields of the obtained single crystals were 1.3-3.8%. Both the intrinsic luminescence of Y 3 Al 5 O 12 (YAG) and the extrinsic luminescence due to each dopant were observed in the radioluminescence spectra. The radioluminescence decay times of YAG doped with either Ti, V, Mn, or Cu were in the range from 6.9 μs to 10.2 ms.

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Luminescence, structure and insight on the inversion degree from normal to inverse spinel in a ZnAl(2−)Fe3+O4 system

Cited by 27 publications

References 73 publications

Effect of Thermochemical Boronizing of Alumina Surface on the Borate Crystals Growth and Interaction with Nickel and Nickel Alloy

Effect of Thermochemical Boronizing of Alumina Surface on the Borate Crystals Growth and Interaction with Nickel and Nickel Alloy

Fabrication, characterization, and antibacterial activity of ferrite, chromite, and aluminate nanoparticles

Photoluminescence and Radioluminescence Properties of Y3Al5O12 Doped with 3d-Transition Metal Ions

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