Yazar "Ibrahim, Jamal Eldin F. M." seçeneğine göre listele

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    Development of Yttrium-Doped BaTiO3 for Next-Generation Multilayer Ceramic Capacitors
    (Amer Chemical Soc, 2023) Tihtih, Mohammed; Ibrahim, Jamal Eldin F. M.; Basyooni, Mohamed A.; En-nadir, Redouane; Belaid, Walid; Hussainova, Irina; Kocserha, Istvan
    The use of electronic devices that incorporate multilayer ceramic capacitors (MLCCs) is on the rise, requiring materials with good electrical properties and a narrow band gap. This study synthesized yttrium-substituted barium titanate (Ba1-xYxTiO3, BYT) using a sol-gel process at 950 degrees C with varying concentrations of yttrium (0 < x < 0.3). X-ray diffraction analysis showed that the tetragonal phase became less pronounced as the yttrium content increased. The samples had varying grain sizes and porosity, with the BY30%T sample having the narrowest band gap at 2.21 eV. The BYT ceramic with 30% yttrium had a thermal conductivity of up to 7 W/m K and an electrical conductivity down to 0.002 (omega cm)-1 at 180 degrees C. The current-voltage characteristics of the BYT MLCC were also studied, showing potential use in next-generation high-capacity MLCCs. This work presents BYT as a promising material for these types of capacitors.
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    Enhanced optical and thermal conductivity properties of barium titanate ceramic via strontium doping for thermo-optical applications
    (Springer, 2023) Tihtih, Mohammed; Ibrahim, Jamal Eldin F. M.; Basyooni, Mohamed A.; En-nadir, Redouane; Belaid, Walid; Abdelfattah, Mohamed M.; Hussainova, Irina
    In this study, we prepared a homogeneous fine powder of barium titanate (BaTiO3, BT) doped with different concentrations of strontium (x = 0, 0.05, 0.125, 0.15, 0.20, and 0.3) and having the composition Ba1-xSrxTiO3 (barium strontium titanate, BSrxT). XRD patterns and Rietveld refinement revealed the existence of a single tetragonal phase structure for BSrxT, x = 0-20%, and a single cubic structure for BSr30%T. The physical properties of the pure and doped mixtures were studied. The results showed that the addition of strontium to the physical properties of BaTiO3, including the apparent porosity, bulk density, linear shrinkage, and water absorption have been changed when increasing the Sr content. Moreover, the inclusion of 15% Sr in BaTiO3 increases the apparent porosity and water absorption of the sample to 6.2 and 28.5%, respectively. The optical properties were investigated by Ultraviolet-visible spectroscopy and it was found that the optical band gap decreases significantly with increasing Sr concentration, from 3.10 for pure BaTiO3 to 2.46 eV for the BSr30%T compound. The thermal conductivity measurements showed that the doping mechanism and the increased temperature have a significant effect on the thermal conductivity results of the fabricated ceramic materials. Therefore, it was found that the value of thermal conductivity increases with increasing Sr doping and at higher temperatures. A correlated behavior of optimum values is observed in band gap energy, absorption, and thermal conductivity which can be exploited for thermo-optical applications.
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    Functionality and Activity of Sol-Gel-Prepared Co and Fe co-Doped Lead-Free BTO for Thermo-Optical Applications
    (Amer Chemical Soc, 2023) Tihtih, Mohammed; Ibrahim, Jamal Eldin F. M.; Basyooni, Mohamed A.; En-nadir, Redouane; Hussainova, Irina; Kocserha, Istvan
    The BTO, BFTC, and BCTF compounds were synthesized by the sol- gel method. The XRD study revealed the formation of single-phase tetragonal perovskite structures with the space group (P4mm). The crystalline parameters were studied as a function of Fe and Co contents and occupation of Ba and/or Ti sites by Fe and Co in the BTO lattice. It was found that the obtained strain increases when Ba2+ is substituted by Co2+ and Ti4+ by Fe3+. The Raman investigation confirmed the existence of three active modes (B1/E (TO1LO), (E (TO)/A1(TO3), and (A 1(LO)/E (TO), all of which are related to the existence of the tetragonal phase and strongly support the XRD results. The microstructural study showed a clear correlation between the presence of Fe and Co and the grain size distribution. Optical studies revealed the improvement in band gap energy with transition-metal (Fe and Co) co-doped BTO ceramics. The decrease in the band gap is explained by the competing effects of Columbian interactions, microdeformation, and oxygen defects. The results indicate that the presence of Fe and Co dopants enhances the absorption in the BTO ceramic. The dopants demonstrated an effect on thermal conductivity: they decreased the thermal conductivity of BTO, which is in the range of 0.76-2.23 W m(-1) K-1 at room temperature and 2.02-0.27 W m(-1) K-1 at elevated temperatures. The microstructure of the manufactured materials and the grain size distribution affect the compressive strength.
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    Iridium/Silicon Ultrathin Film for Ultraviolet Photodetection: Harnessing Hot Plasmonic Effects
    (Wiley-V C H Verlag Gmbh, 2024) Basyooni, Mohamed A.; Tihtih, Mohammed; Boukhoubza, Issam; Ibrahim, Jamal Eldin F. M.; En-nadir, Redouane; Abdelbar, Ahmed M.; Rahmani, Khalid
    The phenomenon of hot carriers, which are generated through the nonradiative decay of surface plasmons in ultrathin metallic films, offers an intriguing opportunity for subbandgap photodetection even at room temperature. These hot carriers possess sufficient energy to inject into the conduction band of a semiconductor material. The groundbreaking use of iridium (Ir) ultrathin film as an ultraviolet (UV) plasmonic material on silicon (Si) for high-performance photodetectors (PHDs) has been successfully demonstrated. Elevating the thickness of the sputtered Ir film to 4 nm yields a notable surge in photocurrent, registering an impressive 600 & mu;A under 365 nm UV illumination with electron mobility of 1.37E3 cm2 V-1 s. This PHD exhibits excellent OFF-ON photoresponses at various applied voltages ranging from 0 to 5 V, maintaining a stable photocurrent. Under UV illumination, it displays exceptional performance, achieving a high detectivity of 1.25E14 Jones and a responsivity of 1.28 A W-1. These outstanding results underscore the significant advantages of increasing the thickness of the Ir film in PHDs, leading to improvements in conductivity, detectivity, external quantum efficiency, responsivity, as well as superior sensitivity for light detection. Exploring hot plasmon effects in iridium/silicon ultrathin films: This study delves into a remarkable ultrasmooth iridium thin film's application in hot electron plasmonic photodetectors. Exciting strides in optoelectronic devices are anticipated, owing to their capability for efficient light modulation, absorption, and conversion, with implications for photodetection and solar energy transformation.image & COPY; 2023 WILEY-VCH GmbH
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    Role of A-site (Sr), B-site (Y), and A, B sites (Sr, Y) substitution in lead-free BaTiO3 ceramic compounds: Structural, optical, microstructure, mechanical, and thermal conductivity properties
    (Elsevier, 2023) Tihtih, Mohammed; Ibrahim, Jamal Eldin F. M.; Basyooni, Mohamed A.; Kurovics, Emese; Belaid, Walid; Hussainova, Irina; Kocserha, Istvan
    Strontium and Yttrium-doped and co-doped BaTiO3 (BT) ceramics with the stoichiometric formulas BaTiO3, B1-xSrxTiO3, Ba1-xYxTiO3, BaTi1-xYxO3, Ba1-xYxTi1-xYxO3, and Ba1-xSrxTi1-xYxO3 (x = 0.075) noted as BT, BSrT, BYT, BTY, BYTY, and BSrTY have been synthesized through sol-gel method. X-ray diffraction (XRD) patterns of the prepared ceramics, calcined at a slightly low temperature (950 degrees C/3h), displayed that BT, BSrT, and BYT ceramics possess tetragonal structures and BTY, BYTY, and BSrTY have a cubic structure. The incorporation of the Ba and/or Ti sites by Sr2+ and Y3+ ions in the lattice of BaTiO3 ceramic and the behaviors of the crystalline characteristics in terms of the Y and Sr dopant were described in detail. The scanning electron microscopy (SEM) images demonstrated that the densification and grain size were strongly related to Sr and Y elements. UV-visible spectroscopy was used to study the optical behavior of the as-prepared ceramic samples and revealed that Sr and Y dopants reduce the optical band gap energy to 2.74 eV for the BSrTY compound. The outcomes also demonstrated that the levels of Urbach energy are indicative of the created disorder following the inclusion of Yttrium. The measurements of the thermal conductivity indicated the influence of the doping mechanism on the thermal conductivity results of the synthesized samples. Indeed, the thermal conductivity of BaTiO3 is decreased with Sr and Y dopants and found to be in the range of 085-2.23 W.m(-1). K-1 at room temperature and decreases slightly with increasing temperature from 2.02 to 0.73-W.m(-1). K-1. Moreover, the microstructure and grains distribution of the BT, BSrT, BYT, BTY, BYTY, and BSrTY samples impacted the compressive strength, hence; the compressive strength was minimized as the grain size decreased.
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    Structural, optical, and electronic properties of barium titanate: experiment characterisation and first-principles study
    (Taylor & Francis Ltd, 2022) Tihtih, Mohammed; Ibrahim, Jamal Eldin F. M.; Basyooni, Mohamed A.; Belaid, Walid; Gomze, Laszlo A.; Kocserha, Istvan
    To study the structural, electronic, and optical properties of lead-free Barium titanate BaTiO3 (BT) ferroelectric material in its tetragonal structure, a combination of experimental and theoretical studies has been used and the obtained results were discussed. The studied BT compound was prepared via the sol-gel technique. The calculated bandgap energy (E-g) and structural parameters of BT are determined using four types of exchange-correlation functionals (PBE, PBEsol, LDA, and PW91) in the perspective of the density functional theory (DFT). XRD and Raman analysis have shown that BT ceramic exhibits a tetragonal phase structure without any trace of impurity phases. The UV-vis investigation showed that BT has a bandgap energy of 3.19 eV, which is larger than the theoretically calculated values. The computed lattice parameter c is overestimated (as large as similar to 1% deviation) when using the LDA approximation. In contrast, PBEsol proved that those lattice constants were close to the experimental values (a deviation of less than 1%).