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Structural, photoluminescence and thermoluminescence study of novel Li+ co-activated lanthanum oxide activated with Dy3+ and Eu3+ obtained by microwave-assisted solution combustion synthesis
摘要： Stimulated luminescence of novel La2O3 nanophosphors doped with Dy3+ and Eu3+ and co-activated with Li+, prepared by microwave-assisted solution combustion synthesis, was investigated for the very first time. X-ray diffraction results indicated hexagonal La2O3 crystalline phase. Lanthanide and Li+ doping did not affect the La2O3 crystal structure. Scanning electron microscopy images showed nanoparticle morphologies such as plates, rods and irregular shapes. Photoluminescence spectra of La2O3:Dy3+, Li+ exhibited blue and green emission bands due to Dy3+ transitions. For La2O3:Eu3+, Li+, sharp emission lines, corresponding to the optical transitions of Eu3+ were observed. Thermoluminescence glow curve of La2O3:Dy3+, Li+ previously exposed to beta radiation exhibited a prominent glow peak located at ～46 °C, possibly useful for after-glow or persistent luminescence applications, whereas La2O3:Eu3+, Li+ curve, displayed three intense peaks at ～50, ～110 and ～150 °C. Thermoluminescent signal repeatability and decay curve asymptotic behaviour could place La2O3:Eu3+, Li+ as suitable for medium and high-dose radiation dosimetry applications.
关键词： Dosimetry,Thermoluminescence,Solution combustion synthesis,La2O3 co-doped nanoparticles
更新于2025-10-22 19:40:53
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Combustion synthesis of α-Si3N4 with green additives
摘要： This paper reports the combustion synthesis of α-Si3N4 using green additives of water and alcohol. The addition of water and alcohol is demonstrated to be effective in controlling the reaction kinetics and improving the formation of α-Si3N4 by vapor reactions. With increasing proportion of additives in the starting composition, the content of α-Si3N4 in the product is clearly enhanced. In contrast to the ammonium halides usually employed as additives in the combustion synthesis of α-Si3N4, the green additives used here are nontoxic, noncorrosive, and thus more attractive for industrial applications.
关键词： Silicon nitride,Combustion synthesis
更新于2025-09-23 15:23:52
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Synthesis of Bismuth Ferrite BiFeO <sub/>3</sub> by solution combustion method
摘要： In this work we describe the synthesis of bismuth ferrite BiFeO3 (BFO) by the method of combustion in solution. Using the techniques of X-ray diffraction (XRD) together with its refinement Rietveld reveals the existence of a distorted rhombohedral perovskite structure (Space group-R3c). The average size of the BFO crystallite was estimated from the half-height width of the X-ray diffraction peaks using the Scherrer’s equation. The morphology of the prepared sample was determined by scanning electron microscopy (SEM) and stoichiometry ratio of BFO was determined by energy dispersive spectroscopy (EDS)
关键词： BFO,X-Ray Diffraction (XRD),Combustion synthesis,Multiferroics
更新于2025-09-23 15:23:52
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Effect of grain size and temperature on DC electrical conductivity of tin oxide nanoparticles synthesized by gel combustion method
摘要： Tin oxide (SnO2) nanomaterials of different grain size have been prepared using gel combustion method by varying the fuel (C6H8O7) to oxidizer (HNO3) molar ratio as a process parameter. The prepared samples were characterized by using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive Analysis X-ray Spectroscope (EDAX). The XRD patterns showed the formation of single phase Tetragonal rutile structure. The average particle size is found to be in the range of 19–34 nm. SEM images show high porosity in the material. The DC electrical conductivity of SnO2 thick film increases with the temperature significantly from 308K to 670K. The DC electrical conductivity of SnO2 thick film decreases with decrease in grain size due to the effect of surface to volume ratio while activation energy increases with decrease of grain size.
关键词： Thick film,Tin oxide,Activation energy,DC conductivity,Combustion synthesis
更新于2025-09-23 15:22:29
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Combustion synthesis and photoelectrochemical characterization of gallium zinc oxynitrides
摘要： We report a rapid combustion synthesis method for producing band gap tunable gallium zinc oxynitrides, a material of interest for water splitting applications. By varying the ratio of zinc and gallium, we can tune the band gap from 2.22 to 2.8 eV. Furthermore, nitrogen can be incorporated up to nearly 50% via replacement of oxygen without the need for high temperatures or an additional ammonolysis step. X-ray photoelectron spectroscopy (XPS) and EDX analysis suggests a preferential segregation of Zn to the surface of the as-synthesized particles, though the surface Ga/Zn molar ratio in the as-synthesized particles is correlated with the Ga/Zn molar ratio of the precursor materials. Photoelectrochemical measurements show that the oxynitride powders are photoactive under both AM1.5 and visible-only (k . 435 nm) irradiation. Hydrogen and oxygen were both evolved in half-reaction experiments under simulated AM1.5 irradiation without externally applied bias, although addition of an OER catalyst did not enhance the rate of oxygen formation, suggesting that intra- and interparticle recombination are signi?cant.
关键词： water splitting,photoelectrochemical,gallium zinc oxynitrides,band gap tuning,combustion synthesis
更新于2025-09-23 15:21:01
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Influence of Precursor Concentration on Structural, Morphological and Optical Properties of Hematite (α-Fe <sub/>2</sub> O <sub/>3</sub> ) Nanoparticles
摘要： Background: We report for the first time that there is a considerable effect on the morphology and optical properties of hematite (α-Fe2O3) nanoparticles by varying the precursor concentrations from 1mmol to 3mmol. The nanoparticles were synthesized by combustion route using ferric nitrate, citric acid and ammonia as precursors at an annealing temperature range of 6000C. Phase purity, morphological studies and optical properties of the products were studied by powder X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Raman spectroscopy and UV Visible spectroscopy. The as-synthesized hematite nanoparticles have a mesoporous granular and somewhat spherical structure with a bulk density ranging from 0.11 to 0.59gmcm-3. Conclusion: The band gap of the as-synthesized α-Fe2O3 nanoparticles decreases from 1.96eV-1.77eV with the decrease in the precursor concentration. Raman spectroscopy confirmed the formation of a hematite phase of iron oxide nanoparticles. Practical percentage yield of the products increased from 47% to 65% with decrease in precursor concentrations.
关键词： α-Fe2O3 nanoparticles,band gap,Optical properties,morphological studies,bulk density,Combustion synthesis
更新于2025-09-23 15:19:57
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A Novel Reddish Orange Luminescent Material Sr3B2O6:Sm3+
摘要： The Sm3+ doped Sr3B2O6 phosphors were synthesized using a solution combustion synthesis method followed by heating of the precursor combustion ash at 1000oC in air. The synthesized phosphors were characterized by powder XRD. The photoluminescence properties of Sm3+-doped Sr3B2O6 were investigated at room temperature. The photoluminescence spectra at room temperature show the f–f transitions typical of Sm3+. The emission spectrum of Sr3B2O6:Sm3+ exhibited four sharp emission peaks corresponding to 4G5/2 → 6H5/2 (563–572 nm), 4G5/2 → 6H7/2 (598–614 nm), 4G5/2 → 6H9/2 (647–666 nm), and 4G5/2 → 6H11/2 (705–714 nm) transitions of Sm3+. The relation between the charge transfer band of Sm3+ ion and the host composition was discussed.
关键词： Sr3B2O6,photoluminescence,combustion synthesis,Sm3+ ion
更新于2025-09-19 17:15:36
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Laser induced ultrafast combustion synthesis of solution-based AlO <sub/>x</sub> for thin film transistors
摘要： Solution processing of amorphous metal oxides using excimer laser annealing (ELA) has been lately used as a viable option to implement large-area electronics, offering high quality materials at a reduced associated cost and process time. However, the research has been focused on semiconductor and transparent conductive oxide layers rather than on the insulator layer. In this work we present amorphous aluminum oxide (AlOx) thin films produced at low temperature (≤150 °C) via combustion synthesis triggered by ELA, for oxide thin film transistors (TFTs) suitable for manufacturing flexible electronics. The study showed that combining ELA and combustion synthesis leads to an improvement in the dielectric thin film’s densification in a shorter time (≤15 min). Optimized dielectric layers were obtained combining a short drying cycle at 150 °C followed by ELA treatment. High breakdown voltage (4 MV cm?1) and optimal dielectric constant (9) was attained. In general, TFT devices comprising the AlOx fabricated with a drying cycle of 15 min followed by ELA presented great TFT properties, a high saturation mobility (20.4 ± 0.9 cm2 V?1 s?1), a small subthreshold slope (0.10 ± 0.01 V dec?1) and a turn-on voltage ≈0 V. ELA is shown to provide excellent quality solution-based high-k AlOx dielectric, that surpass other methods, like hot plate annealing and deep ultraviolet (DUV) curing. The results achieved are promising and expected to be of high value to the printed electronic industry due to the ultra-fast film densification and the surface/area selective nature of ELA.
关键词： thin film transistors,excimer laser annealing,solution processing,amorphous metal oxides,combustion synthesis,flexible electronics
更新于2025-09-19 17:13:59
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Cymbopogoncitratus assisted green synthesis of doped Yttrium nanopowder: Structural and Photoluminescence properties for wLEDs applications
摘要： For the first time green route was used to synthesize pure and Cr3+ (1-11 mol %) doped Yttrium oxide (Y2O3) nanostructures by using Cymbopogon citrates extract as a fuel. The prepared samples were well characterized by powder X-ray diffraction (PXRD), transmission electron microscopy, Diffused reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The PXRD results shows the formation of single phase, cubic structure of Y2O3 with crystallite sizes ~15 nm which was further confirmed by TEM results. The SEM results indicated various shaped nanostructures which solely dependent on the fuel concentration. The band gap energy was estimated by DRS and found to be in the range of 5.67 – 5.80 eV. PL results indicate intense sharp peak at ~ 689 nm along with vibronic side bands 706 and 734 nm. The 689 nm peak was well known R – line and was assigned to the 2Eg → 4A2g transition of Cr3+ions.The CIE (Commission International de I'E' clairage) chromaticity coordinates were located in pure orange- red region. Further, (Commission International de I'E' clairage) CCT values were in the range 3387 – 3486 K. The studies indicate that Y2O3:Cr3+nanophosphors (NPs) were quite useful for display devices.
关键词： display devices,orange-red emission,Cymbopogon citrates,Green combustion synthesis,Photoluminescence
更新于2025-09-16 10:30:52
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Fabrication of La2O3 Uniformly Doped Mo Nanopowders by Solution Combustion Synthesis Followed by Reduction under Hydrogen
摘要： This work reports the preparation of La2O3 uniformly doped Mo nanopowders with the particle sizes of 40–70 nm by solution combustion synthesis and subsequent hydrogen reduction (SCSHR). To reach this aim, the foam-like MoO2 precursors (20–40 nm in size) with different amounts of La2O3 were first synthesized by a solution combustion synthesis method. Next, these precursors were used to prepare La2O3 doped Mo nanopowders through hydrogen reduction. Thus, the content of La2O3 used for doping can be accurately controlled via the SCSHR route to obtain the desired loading degree. The successful doping of La2O3 into Mo nanopowders with uniform distribution were proved by X-ray photon spectroscopy and transmission electron microscopy. The preservation of the original morphology and size of the MoO2 precursor by the La2O3 doped Mo nanopowders was attributed to the pseudomorphic transport mechanism occurring at 600 ?C. As shown by X-ray diffraction, the formation of Mo2C impurity, which usually occurs in the direct H2 reduction process, can be avoided by using the Ar calcination-H2 reduction process, when residual carbon is removed by the carbothermal reaction during Ar calcination at 500 ?C.
关键词： hydrogen reduction,La2O3,Mo nanopowder,doping,solution combustion synthesis
更新于2025-09-10 09:29:36