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Propose for Raman mode position for Mn-doped ZnO nanoparticles
摘要： Raman scattering used to study Mn-doped ZnO and pressurized Mn-doped ZnO for various dopant concentrations and pressures. Since none of the Zn sites are preferred to other Zn sites by default, the likelihood of replacing Zn with Mn is the same for each Zn site in the ZnO lattice. That is, Mn substitution should be visible throughout the Raman spectrum of ZnO with different degrees of effectiveness due to Mn substitution. We observe this affection in two different regions related to Zn -and O- regions. We believe if we want to see the effect of Mn doping these two regions must be considered. Based on this belief, we disagree with some of the previous Mn-related modes assignment. These modes are either due to combinations modes of ZnO itself or to silent modes of ZnO activated under Raman selection rules caused by the breakdown of the translational symmetry of the crystal lattice.
关键词： Raman scattering,Mn dopant,Wurtzite structure,Pressure
更新于2025-09-04 15:30:14
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Structural and optoelectronic properties of Ce-Al2O3 nanoparticles prepared by sol-gel precursors
摘要： Pure and Ce-doped Al2O3 nanoparticles (NPs) were synthesized in different cerium percentages of 1%, 2%, and 3% by cerium chloride and aluminum nitrate precursors in the presence of powerful reducing agent-NaBH4 and CTAB stabilizers using sol-gel method. To examine the crystal, morphological, optical, and electronic properties, the XRD, FESEM, TEM, FTIR, UV-DRS, and PL analyses were used for the heated samples in 1000 °C for 4 hours. The XRD analysis indicated that the pure sample has γ, δ and θ phases, and the structure remained unchanged when Ce impurity was increased. The EDS analysis showed that the percentage of Al element was 47.40 wt% in the pure sample and that it increased to 53.83 wt% for 1% doped sample increasing Al ions in tetrahedral and octahedral sites of alumina through increasing Ce impurities. The TEM results revealed the sphere-like particles with mean particle size of 26 nm in diameter at a 3% level of impurity. The FTIR result showed that an increase in AlO4 adsorption peak in 821 cm-1 compared to AlO6 adsorption peak in 619 cm-1 was due to the dominance of vibrating bonds of tetrahedral sites rather than octahedral sites in alumina. The optical UV-DRS analysis also demonstrated the redshift configuration in a sample by increasing Ce dopant and reducing energy bandgap from 4.10 to 3.26 eV for pure and 3% Ce-doped Al2O3 NPs, respectively. Finally, the photoluminescence (PL) results indicated that increasing Ce dopant reduced electron-hole recombination leading to an increase in photocatalytic activity.
关键词： Chemical Synthesis,Cerium dopant,Sol-gel,Ceramics,Al2O3 NPs
更新于2025-09-04 15:30:14
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[IEEE 2018 International Semiconductor Conference (CAS) - Sinaia, Romania (2018.10.10-2018.10.12)] 2018 International Semiconductor Conference (CAS) - Comparative Study of Sm and La Doped ZnO Properties
摘要： Samarium and Lanthanum doped nanostructured ZnO thin films were grown onto glass substrates by spray deposition method. Influences of different concentrations (0% to 1%) of Sm and La on the ZnO structural and optical properties were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), Raman spectroscopy and by UV-VIS spectroscopy. X-ray diffraction studies revealed that the ZnO films have zincite crystalline structure and show a preferential growth orientation along (101) crystallographic orientation. Doping with Sm and La leads to changes of thin films crystallinity as well as their transparency in VIS region of electromagnetic spectrum. Increasing dopant concentration leads to slightly increased transparency.
关键词： samarium,zinc oxide,optical properties,Lanthan,dopant
更新于2025-09-04 15:30:14
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AIP Conference Proceedings [Author(s) 4TH ELECTRONIC AND GREEN MATERIALS INTERNATIONAL CONFERENCE 2018 (EGM 2018) - Bandung, Indonesia (27–28 July 2018)] - Effects of Ag dopant and ultraviolet irradiation on structural properties of zinc oxide nanostructures
摘要： ZnO nanorods are promising UV light driven photocatalyst for the degradation of organic dyes. In this work, the effects of Ag dopant (0.02 to 0.1 mol%) and ultraviolet irradiation (0 to 6 min) on structural, optical and photocatalytic properties of zinc oxide nanorods were investigate. The Ag incorporation ZnO nanoraod have been grown on glass substrate by chemical solution deposition method. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV–vis absorption spectroscopy (UV–vis). The XRD spectra of the Ag incorporation ZnO (Ag-ZnO) films indicate that Ag was incorporated in the wurtzite hexagonal crystal structure of ZnO and the crystallinity were enhanced with increasing of Ag amount as well as ultraviolet irradiation time. SEM micrographs of pure ZnO films revealed the uniform distribution of rod-like nanostructure of size of about 30-40 nm. Increasing Ag amount as well as irradiation time stimulated the optical properties of ZnO nanostructures. The photocatalytic activity of these nanostructures was evaluated by analysing UV irradiation degradation of methyl orange (MO) dye and it was observed that Ag-ZnO show significantly enhanced photocatalytic activity for degradation of MO, as compared to ZnO nanorods.
关键词： structural properties,ZnO nanorods,ultraviolet irradiation,Ag dopant,photocatalytic activity
更新于2025-09-04 15:30:14