Cathodoluminescence Microanalysis of Irradiated Microcrystalline and Nanocrystalline Samarium Doped BaFCl

2012 ◽  
Vol 18 (6) ◽  
pp. 1229-1238 ◽  
Author(s):  
Marion A. Stevens-Kalceff ◽  
Zhiqiang Liu ◽  
Hans Riesen
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Fine Structure ◽  
Particle Surface ◽  
Host Lattice ◽  
Oxidation States ◽  
Precipitation Method ◽  
Vacancy Defects ◽  
X Ray ◽  
Co Precipitation

AbstractBaFCl:Sm3+ is an efficient photoluminescent storage phosphor for ionizing radiation. Cathodoluminescence (CL) microanalysis enables the Sm2+ and Sm3+ oxidation states of samarium doped BaFCl to be easily identified, provides information about electron-beam and X-ray induced modification of BaFCl:Sm, and enables the synthesis dependent spatial distribution of samarium dopants of <100 ppm concentration to be determined with sub-100 nm resolution at 295 K. CL spectroscopy of BaFCl:Sm particles reveals broad CL emissions at ∼360 and ∼500 nm associated with Vk(Cl−) and oxygen-vacancy defects in the BaFCl host lattice and fine structure CL emissions associated with major 4GJ → 6HJ (Sm3+) and 5DJ → 7FJ (Sm2+) transitions. CL microanalysis shows samarium dopants are uniformly distributed in conventional sintered microcrystalline BaFCl:Sm. In contrast, CL investigations reveal that for BaFCl:Sm nanoparticles, which have been prepared using a co-precipitation method, with greatly improved Sm3+ → Sm2+ conversion efficiency, the samarium dopants are concentrated near the particle surface resulting in a BaFCl:Sm3+ shell surrounding the BaFCl core, which is stable to energetic irradiation.

Structural Properties of Cu-Doped ZnO Prepared by Coprecipitation Method

2021 ◽  
Vol 1028 ◽  
pp. 90-95
Author(s):  
Kharisma Noor Afifah Supoyo ◽  
Mohammad Syaiful Anwar ◽  
Retno Asih ◽  
Malik Anjelh Baqiya ◽  
Prae Chirawatkul ◽  
...  
Keyword(s):  
Structural Properties ◽  
Hexagonal Wurtzite Structure ◽  
Host Lattice ◽  
Precipitation Method ◽  
Zno Nanoparticle ◽  
X Ray ◽  
As Doping ◽  
Refinement Method ◽  
Co Precipitation ◽  
X Ray Absorption

An experimental study to determine the effect of Cu doping on structural properties of ZnO nanoparticle has been conducted. Zn1-xCuxO (CZO) were prepared by co-precipitation method by varying Cu concentration with x = 0.00, 0.10, 0.11 and 0.12. The structural properties of the CZO sample were characterized by X-Ray diffraction (XRD) and X-ray Absorption Spectroscopy (XAS), which consist of XANES (X-ray Absorption Near-Edge Spectroscopy) and EXAFS (Extended X-ray Absorption Fine Structure). XAS measurements were performed in the energy of Cu K-edge and Zn K-edge using synchrotron radiation at SLRI (Synchrotron Light Research Institute) in Thailand. Both Cu K-edge and Zn K-edge XANES spectra indicate that the oxidation states of Cu and Zn ions are 2+. Analysis of XRD data with refinement method using Rietica software confirms the presence of Cu as doping in ZnO host lattice with the crystallite size ranging between 26 and 44 nm. Moreover, it shows that the obtained CZO samples are polycrystalline with (002) predominant reflection and exhibit a hexagonal wurtzite structure.

scholarly journals Photoluminescent Properties of Hydroxyapatite and Hydroxyapatite/Multi-Walled Carbon Nanotube Composites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Hexagonal Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multi Walled Carbon Nanotube ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Co Precipitation ◽  
Functionalized Mwcnts

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.

scholarly journals Evaluation of Fe-Mg Binary Oxide for As (III) Adsorption—Synthesis, Characterization and Kinetic Modelling

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 805
Author(s):  
Saif Ullah Khan ◽  
Rumman Zaidi ◽  
Feroz Shaik ◽  
Izharul Haq Farooqi ◽  
Ameer Azam ◽  
...  
Keyword(s):  
Arsenic Removal ◽  
Kinetic Modelling ◽  
Arsenic Concentration ◽  
Experimental Studies ◽  
Precipitation Method ◽  
Arsenic Adsorption ◽  
Adsorbent Dosage ◽  
X Ray ◽  
Co Precipitation ◽  
Contaminated Waters

Nanotechnology has received much attention in treating contaminated waters. In the present study, a facile co-precipitation method was employed to synthesize a novel iron and magnesium based binary metal oxide using a stoichiometrically fixed amount of FeNO3.9H2O and MgNO3.6H2O in a proportion of molar concentration 1:1 and was later evaluated in removing As (III) from contaminated waters. Characterization of the prepared nanomaterial was done using X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-Ray Analysis (EDAX) and ultraviolet–visible spectrophotometry (UV-VIS). Experimental studies on batch scale were carried out, examining the effect of varying initial concentrations of metal, adsorbent dosage, application time and initial pH on removal efficiency. Arsenic removal increased on increasing adsorbent dosage (0.1–1 g/L) but trend reversed on increasing initial arsenic concentration attaining qmax of 263.20 mg/g. Adsorption was quite efficient in pH range 4–8. Freundlich fitted better for adsorption isotherm along with following Pseudo-2nd order kinetics. The reusability and effect of co-existing ions on arsenic adsorption, namely SO42−, CO32− and PO43− were also explored with reusability in 1st and 2nd cycles attained adsorptive removal up to 77% and 64% respectively. The prepared nano-adsorbent showed promising results in terms of high arsenic uptake (qmax of 263.20 mg/g) along with facile and cost-effective synthesis. Thus, the co-precipitation technique used in this work is a simple one step procedure without any use of any precursor as compared to most of the other procedures used for synthesis.

Photocatalytic Activity of Fe-Doped ZnO/Montmorillonite Nanocomposite for Degradation of Malachite Green

2015 ◽  
Vol 827 ◽  
pp. 19-24 ◽  
Author(s):  
Nur Afifah ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh
Keyword(s):  
Photocatalytic Activity ◽  
Malachite Green ◽  
Organic Dyes ◽  
Uv Light ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Resonance ◽  
Doped Zno ◽  
Co Precipitation

In this study, the photocatalytic activity of pure Fe- doped ZnO and Fe- doped ZnO/Montmorillonite nanocomposite has been investigated for the degradation of malachite green under UV light irradiation. Both photocatalysts were synthesized using co-precipitation method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier-transform infrared absorption, and electron spin resonance. The results showed that the photocatalytic efficiency is better in the presence of montmorillonite compared to pure Fe- doped ZnO. To detect the possible reactive species involved in degradation of organic dyes control experiments with introducing scavengers into the solution of organic dyes were carried out. It is found that electron plays an important role in the degradation of malachite green.

Template Induced Synthesis of Nano-Hydroxyapatite by Co-Precipitation Method

2011 ◽  
Vol 311-313 ◽  
pp. 1713-1716 ◽  
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Chang An Wang ◽  
Li Guo Ma ◽  
Feng Liu
Keyword(s):  
Electron Microscope ◽  
Chondroitin Sulfate ◽  
Aspartic Acid ◽  
Transmission Electron Microscope ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Co Precipitation

Nano-hydroxyapatite with different morphology was synthesized by the co-precipitation method coupled with biomineralization using Ca(NO3)2•4H2O and (NH4)2HPO4 as reagents, adding chondroitin sulfate, agarose and aspartic acid as template. The structure and morphology of the prepared powders were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM).

Synthesis of Silica Modified Large-Sized Hydroxyapatite Whiskers by a Hydrothermal Co-Precipitation Method

2015 ◽  
Vol 645-646 ◽  
pp. 1339-1344 ◽  
Author(s):  
Yan Ting Yin ◽  
Qing Hua Chen ◽  
Ting Ting Yan ◽  
Qing Hua Chen
Keyword(s):  
Bone Repair ◽  
Ethanol Solution ◽  
Morphological Properties ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Type ◽  
Ft Ir ◽  
Co Precipitation ◽  
Surface Modified

The objective of this study was to develop a novel silica modified large-sized hydroxyapatite whiskers with improved properties for use in bone repair applications. Large-sized whiskers with a mean length of 250μm were obtained by a hydrothermal co-precipitation method at 150°C, 7.5Mpa in high-pressure reactor. Silica modified hydroxyapatite whiskers were prepared by dissolving TEOS in ethanol solution, then sintering with hydroxyapatite. The compositional and morphological properties of prepared whiskers were studied by means of x-ray diffraction (XRD), Fouier transform infrared (FT-IR), scanning electron microscopy (SEM). The results indicated the evidence of nanosilicon dioxide particles on the surface of HAP whiskers. The size of nanosilicon dioxide particles depends on dropping and stirring rate. Hence, this new type of silica modified large-sized hydroxyapatite whiskers is a valuable candidate for biomedical applications.Key words: hydroxyapatite, hydrothermal co-precipitation, surface modified, whiskers

scholarly journals Structure of the manganese complex in photosystem II: insights from X–ray spectroscopy

2002 ◽  
Vol 357 (1426) ◽  
pp. 1347-1358 ◽  
Author(s):  
Vittal K. Yachandra
Keyword(s):  
Fine Structure ◽  
Emission Spectroscopy ◽  
Structural Models ◽  
Oxidation States ◽  
X Ray ◽  
X Ray Scattering ◽  
Raman Process ◽  
Mn Cluster ◽  
X Ray Absorption ◽  
S States

We have used Mn K–edge absorption and Kβ emission spectroscopy to determine the oxidation states of the Mn complex in the various S states. We have started exploring the new technique of resonant inelastic X–ray scattering spectroscopy; this technique can be characterized as a Raman process that uses K–edge energies (1s to 4p, ca . 6550 eV) to obtain L–edge–like spectra (2p to 3d, ca . 650 eV). The relevance of these data to the oxidation states and structure of the Mn complex is presented. We have obtained extended X–ray absorption fine structure data from the S 0 and S 3 states and observed heterogeneity in the Mn–Mn distances leading us to conclude that there may be three rather than two di– μ –oxo–bridged units present per tetranuclear Mn cluster. In addition, we have obtained data using Ca and Sr X–ray spectroscopy that provide evidence for a heteronuclear Mn1Ca cluster. The possibility of three di– μ –oxo–bridged Mn–Mn moieties and the proximity of Ca is incorporated into developing structural models for the Mn cluster. The involvement of bridging and terminal O ligands of Mn in the mechanism of oxygen evolution is discussed in the context of our X–ray spectroscopy results.

scholarly journals Nitrogen and Bromide Co-Doped Hydroxyapatite Thin Films with Antimicrobial Properties

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1505
Author(s):  
Simona Liliana Iconaru ◽  
Carmen Steluta Ciobanu ◽  
Daniela Predoi ◽  
Mikael Motelica-Heino ◽  
Constantin Cătălin Negrilă ◽  
...  
Keyword(s):  
Thin Films ◽  
Antimicrobial Activity ◽  
Spin Coating ◽  
Thin Layers ◽  
Precipitation Method ◽  
X Ray ◽  
Co Precipitation ◽  
First Time ◽  
Co Doped

Hydroxyapatite (Ca10(PO4)6(OH)2, HAp), due to its high biocompatibility, is widely used as biomaterial. Doping with various ions of hydroxyapatite is performed to acquire properties as close as possible to the biological apatite present in bones and teeth. In this research the results of a study performed on thin films of hydroxyapatite co-doped with nitrogen and bromine (NBrHAp) are presented for the first time. The NBrHAp suspension was obtained by performing the adapted co-precipitation method using cetyltrimethylammonium bromide (CTAB). The thin layers of NBrHAp were obtained by spin-coating. The stability of the NBrHAp suspension was examined by ultrasound measurements. The thin layers obtained by the spin-coating method were examined by scanning electron microscopy (SEM), optical microscopy (OM), and metallographic microscopy (MM). The presence of nitrogen and bromine were highlighted by energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) studies. Fourier transform infrared spectroscopy (FTIR) was used to highlight the chemical status of nitrogen and bromine. In addition, the powder obtained from the NBrHAp suspension was analyzed by XRD. Moreover, the in vitro antimicrobial activity of the NBrHAp suspensions and coatings was investigated using the reference microbial strains Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231. The results highlighted the successful obtainment of N and Br co-doped hydroxyapatite suspension for the first time by an adapted co-precipitation method. The obtained suspension was used to produce pure NBrHAp composite thin films with superior morphological properties. The NBrHAp suspensions and coatings exhibited in vitro antimicrobial activity against bacterial and fungal strains and revealed their good antimicrobial activity.

scholarly journals The Effect of Polyvinyl Alcohol Concentration on the Growth Kinetics of KTiOPO4 Nanoparticles Synthesized by the Co-precipitation Method

2020 ◽  
Vol 1 (4) ◽  
pp. 187-193
Author(s):  
Elaheh Gharibshahian
Keyword(s):  
Polyvinyl Alcohol ◽  
Shape Control ◽  
Second Harmonic ◽  
Precipitation Method ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Size And Shape ◽  
Diffraction Patterns ◽  
Co Precipitation

KTiOPO4 nanoparticles are known as the best candidate to utilize for second-harmonic generation in multiphoton microscopes and bio labels. Size and shape are important and effective parameters to control the properties of nanoparticles. In this paper, we will investigate the role of capping agent concentration on the size and shape control of KTP nanoparticles. We synthesized KTP nanoparticles by the co-precipitation method. Polyvinyl alcohol with different mole ratios to titanium ion (1:3, 1:2, 1:1) was used as a capping agent. Products were examined by X-ray diffraction patterns and scanning electron microscopy analyses. X-ray diffraction patterns confirmed the formation of the KTP structure. The biggest (56.36nm) and smallest (39.42nm) grain size were obtained by 1:3 and 1:1 mole ratios of capping agent, respectively. Dumbly, spherical and polyhedral forms of KTP nanoparticles were observed by the change in capping agent mole ratio. The narrowest size distribution of KTiOPO4 nanoparticles was obtained at 1:1 mole ratio of capping agent. Doi: 10.28991/HIJ-2020-01-04-06 Full Text: PDF

Sign in / Sign up

Export Citation Format

Share Document