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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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Multivariable study on growth of diamond on diamond substrates by microwave? plasma chemical vapour deposition
摘要： Substrate temperature and methane concentration in Hydrogen (H2) gas mixture is the main source for increasing the growth rate, nucleation and grain size of a synthetic diamond. The downside of such an approach is reduced quality. By increasing the chamber pressure, although the quality can be improved, however, it leads to a decrease in the crystal growth rate. Thin diamond films were deposited under hydrogen (H2) and methane (CH4) gas mixture using microwave plasma chemical vapor deposition (MPCVD) technique. The effect of methane concentration (1-5%), growth temperature, and pressure on the nucleation of diamond thin films on diamond substrates was investigated. The growth temperature and pressure were maintained in the range of 925-950 ℃ and 72-75 Torr, respectively. Single crystal diamond (SCD) thin films have been prepared on diamond substrates, which play an important role in the application of the diamond detectors. Different dimensions of films were obtained on diamond substrates with different thicknesses such as 209.17 μm, 401.73 μm, and 995.03μm for the sample with 1%, 2% and 5% of methane concentration respectively. The roughness, as well as growth rate of these films, were also investigated and were found to be 5.02 μ/h and 4.23 nm, respectively for 5% methane by optimizing the substrate temperature at 950 ℃. Different characterization techniques were used to study the structural, morphological, and compositional properties of the deposited diamond films which confirmed the crystallographic order of the developed diamond film on the diamond substrates.
关键词： MPCVD,XRD,Diamond thin films,XPS,Raman spectroscopy,AFM,SEM
更新于2025-09-23 15:23:52
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Structural, optical and magnetic elucidation of co-doped of Nd+3 and Pr+3 on lithium nanoferrites and its technological application
摘要： LiNiCo spinel ferrites were prepared, by doping with rare earth metals Nd and Pr, according to micro-emulsion method. In order to study the effect of Nd and Pr, the crystal structure and magnetic properties of prepared ferrites were scrutinized in detail. The endorsement of single-phase spinel ferrites with the co-occurrence of orthophase was confirmed by XRD and FTIR. The average crystallite size varied with increasing the doped concentration of Nd and Pr, which is in the range from 28nm to 70nm. Magnetic properties were analyzed by VSM within range of -10000Oe and 10000Oe. MS and MR values decreased with the increase in concentration. The value of HC, MR, and MS showed stability for transformer core where electromagnetic interference is reduced. Hence synthesized ferrites LiNi0.35-yCo0.15PryNdxFe2-xO4 are suitable for transformers and induction.
关键词： Microemulsion,XRD,Li-Pr,Neodymium,Nanocrystalline ferrites,Praseodymium,Magnetic properties
更新于2025-09-23 15:23:52
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Crystal growth, structural and electrical properties of (Cu1-Ag )7GeS5I superionic solid solutions
摘要： Single crystals of (Cu1-хAgx)7GeS5I solid solutions were grown by vertical zone crystallization method. XRD studies have shown that they crystallize in face-centered cubic lattice of the argyrodite structure (space group F m4 3 , Z = 4). Structural studies were performed on the basis of original structure model by means of Rietveld re?nement method. Electrical measurements were carried out in the temperature interval 300–360 K and in the range of frequencies 10 Hz–10 GHz. Temperature and frequency dependences of electrical conductivity were analyzed. In?uence of cation substitution on the electrical conductivity as well as relationship between structural and electrical properties of (Cu1-хAgx)7GeS5I solid solutions were studied.
关键词： Arrhenius law,XRD studies,Superionic conductor,Impedance spectroscopy,Electrical conductivity
更新于2025-09-23 15:23:52
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Structural, photoluminescence and magnetic properties of Cu-doped SnO2 nanoparticles co-doped with Co
摘要： Co doped Sn0.98Cu0.02O2 nanoparticles have been synthesized by co-precipitation method. The prepared nanoparticles were characterized by X-ray diffraction, scanning electron microscope (SEM), transmission electron microscopy, Fourier transform infrared spectroscopy, photoluminescence and magnetic measurements. The observed tetragonal rutile structure confirmed by XRD patterns was not altered by Co-doping and the value of average crystallite size lies within 8–14 nm. The formation of high density defect states and the new phases of Co and Sn were responsible for the reduction of energy gap (Eg) with Co-doping; Eg varied between 3.12 and 3.58 eV. The tuning of band gap and luminescence properties by Co-doping suggested that Co = 4% doped sample is a promising material for selective coatings for solar cells; use as antireflective coating materials, and for fabrication of optoelectronic devices. FTIR spectrum has been used to authenticate the formation of Sn–O bond and the existence of Co in Sn–Cu–O. The promotion of higher local disorders and the oxygen-related defects during growth process of SnO2 nanoparticles at Co = 4% is responsible for the higher UV/violet/blue band photoluminescence emission intensity. The overlapping between bound magnetic polarons (BMP) by Co-doping induced the room temperature ferromagnetism. The existence of high density charge carriers and oxygen vacancies at Co = 4% sample might be responsible for highest magnitude of ferromagnetism. The noticed suppression of RTFM at Co = 6% may be due to the enhanced antiferromagnetic interaction between neighbouring Co–Co ion.
关键词： Photoluminescence,SnO2 nanoparticles,XRD,Energy gap,Magnetic properties
更新于2025-09-23 15:23:52
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AIP Conference Proceedings [Author(s) 1ST INTERNATIONAL CONGRESS ON SOLAR ENERGY RESEARCH, TECHNOLOGY AND APPLICATIONS (ICSERTA 2018) - Ouarzazate, Morocco (8–10 May 2018)] - Synthesis and MID-IR characterization of strontium hexaferrite nanoparticles using gel to crystallization technique
摘要： Synthesis and MID-IR characterization of strontium hexaferrite nanoparticles using gel to crystallization technique. Strontium hexaferrite (SrFe12O19) nanoparticles have been synthesized using gel to crystallization technique. Citric acid, iron nitrate and strontium nitrate were used as starting materials to prepare the gel. The prepared gel was heated at 100°C for 4 hrs in muffle furnace and sample was annealed at 800°C for 4 hrs. The prepared sample was characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The XRD pattern confirms the formation of single phase SrFe12O19 nanoparticles. The FTIR spectrum shows the absorption bands in the range 400-600 cm-1 which are assigned to metal-oxygen vibrations. The prepared nanoparticles show the formation of single phase and can be used for various applications such as magnetic recording media, microwave devices and permanent magnets.
关键词： XRD,FTIR,gel to crystallization,Strontium hexaferrite,nanoparticles
更新于2025-09-23 15:23:52
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Development of UVB Radiation-Emitting Gd3+-Doped Na3YSi2O7 Host Material
摘要： In this work, we synthesized and characterized a narrow-band, ultraviolet-emitting Na3YSi2O7:Gd3+ material. A series of Na3Y1-xSi2O7:Gdx (x = 0.01 ≤ x ≤ 0.11) samples were synthesized using a sol–gel process. X-ray diffraction patterns of all the samples were found to be similar to the hexagonal Na3YSi2O7 phase. Morphology and functional group analysis were performed using scanning electron microscopy and Fourier transform infrared spectroscopy. The effects of gadolinium concentration on the luminescence intensity of the Na3YSi2O7:Gd3+ samples were investigated. The developed sample exhibited an ultraviolet emission peaking at 313 nm under 273-nm excitation. The dominant band at 313 nm was attributed to 6P7/2 → 8S7/2 transition of Gd3+ ions. The electron paramagnetic resonance (EPR) studies revealed the presence of Gd3+ ions in octahedral Y3+ sites in the host lattice.
关键词： EPR,Na3YSi2O7,photoluminescence,XRD,Gd3+ ions,Sol–gel
更新于2025-09-23 15:22:29
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Preparation, characterization and photocatalytic evaluation of aluminum doped metal ferrites
摘要： Spinel ferrite nano-particles have shown a growing interest in recent years due to their specific magnetic and electrical properties. In this manuscript different types of metal ferrites were prepared and doped with different amounts of Al. Full characterization of the prepared ferrites was performed using X-Ray spectrophotometer (XRD), Electron paramagnetic resonance(EPR), and BET surface area measurements. Photo catalytic activity for degradation of organic dye was examined also for all samples. The results showed that the doping of ferrites with Aluminum make a dramatic change in the photocatalytic behavior. A correlation between the structure and magnetic proprieties with the photocatalytic behavior was evaluated.
关键词： BET,Aluminum dopant,EPR,Ferrites,XRD,Photocatalyst
更新于2025-09-23 15:22:29
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Temperature effect on structural, optical and NH<SUB align="right">3 gas sensing properties of TeO<SUB align="right">2 thin films
摘要： TeO2 thin films with different temperatures (400, 450 and 500°C) were deposited on glass substrates by thermal evaporation technique from a Te powder. XRD patterns indicate that as the temperature increases, the crystallisation improves. Observing the images obtained by SEM, it is seen that the grain size decreases as the temperature increases. The optical energy gap of the films was determined from transmittance and reflectance spectra. The optical energy gap decreased continuously from 3.95 eV to 3.80 eV with increasing temperature. Studying the effect of deposition temperature on NH3 gas measurement, it became obvious that as the deposition temperature increases, the sensitivity increases and the response and recovery times decrease.
关键词： scanning electron microscope,XRD,thin films,sensitivity,X-ray diffraction,energy gap,SEM,optical
更新于2025-09-23 15:22:29
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Improved Photocatalytic Properties of NiS Nanocomposites Prepared by Displacement Method for Removal of Rose Bengal Dye
摘要： Objective: The present work describes NiS nanoparticles were prepared by chemical displacement method using CTAB as a stabilizer. Method: For the source of Sulfide ion, we used thioacetamide as fuel and nickel nitrate as metal salt. NiS nanoparticles are p-type semiconductor. Band gap of NiS is 0.5- 0.6 eV and also reported to be a good photo catalyst in the degradation of pollutants. The structural, morphological, metal percentage and optical properties of as synthesized nanoparticles are investigated by using X-ray diffraction (XRD), UV-Visible spectra; Field emission gun scanning electron microscopy (FEG-SEM) with EDS, Fourier transforms infrared spectroscopy (FTIR), High-resolution transmission electron microscopy (HR-TEM) and Photoluminescence spectroscopy (PL). Results: The x-ray diffraction patterns revealed that the particles exhibited a crystal structure at the suitable temperature. The average particle size of the nanoparticles from the X-ray diffraction is about 22.8 nm and also Field emission gun scanning electron microscopy shows good morphology and exhibited clearly hexagonal shape. Conclusion: The Transmission electron microscopy (HR-TEM) shows the crystalline size of structures is 22 nm. Further, the Photocatalytic activity of Synthesized NiS nanoparticles was investigated by photo catalytic removal of Rose Bengal as a model of organic pollutant. It shows good photocatalytic activity against Rose Bengal dye (98.1%).
关键词： Nanoparticles,UV-Vis,FEG-SEM,EDAX,XRD,FTIR,HR-TEM,nickel sulfide
更新于2025-09-23 15:22:29