scholarly journals Synthesis, Structure, and Luminescent Properties of Europium-Doped Hydroxyapatite Nanocrystalline Powders

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Carmen Steluta Ciobanu ◽  
Simona Liliana Iconaru ◽  
Florian Massuyeau ◽  
Liliana Violeta Constantin ◽  
Adrian Costescu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Textural Properties ◽  
Average Crystallite Size ◽  
Luminescent Properties ◽  
Nanocrystalline Powders ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vibrational Studies ◽  
20 Nm

The luminescent europium-doped hydroxyapatite (Eu:HAp, Ca10−xEux(PO4)6(OH)2) with0≤x≤0.2nanocrystalline powders was synthesized by coprecipitation. The structural, morphological, and textural properties were well characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The vibrational studies were performed by Fourier transform infrared, Raman, and photoluminescence spectroscopies. The X-ray diffraction analysis revealed that hydroxyapatite is the unique crystalline constituent of all the samples, indicating that Eu has been successfully inserted into the HAp lattice. Eu doping inhibits HAp crystallization, leading to a decrease of the average crystallite size from around 20 nm in the undoped sample to around 7 nm in the sample with the highest Eu concentration. Furthermore, the samples show the characteristic5D0→7F0transition observed at 578 nm related to Eu3+ions distributed on Ca2+sites of the apatitic structure.

Nanoporous Ni and Ni-Cu Fabricated by Dealloying

2009 ◽  
Vol 1228 ◽  
Author(s):  
Masataka Hakamada ◽  
Yasumasa Chino ◽  
Mamoru Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Noble Metals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Difference ◽  
20 Nm ◽  
Good Workability ◽  
Scanning Electron

AbstractMetallic nanoporous architecture can be spontaneously attained by dealloying of a binary alloy. The nanoporous architecture can be often fabricated in noble metals such as Au and Pt. In this study, nanoporous Ni, Ni-Cu are fabricated by dealloying rolled Ni-Mn and Cu-Ni-Mn alloys, respectively. Unlike conventional Raney nickel composed of brittle Ni-Al or Cu-Al intermetallic compounds, the initial alloys had good workability probably because of their fcc crystal structures. After the electrolysis of the alloys in (NH4)2SO4 aqueous solution, nanoporous architectures of Ni and Ni-Cu with pore and ligament sizes of 10–20 nm were confirmed by scanning electron microscopy and transmission electron microscopy. X-ray diffraction analyses suggested that Ni and Cu atoms form a homogeneous solid solution in the Ni-Cu nanoporous architecture. The ligament sizes of nanoporous Ni and Ni-Cu were smaller than that of nanoporous Cu, reflecting the difference between diffusivities of Ni and Cu at solid/electrolyte interface. Ni can reduce the pore and ligament sizes of resulting nanoporous architecture when added to initial Cu-Mn alloys.

Preparation and Luminescence Properties of ZnS: Cu/Fe Nanocrystalline

2014 ◽  
Vol 1033-1034 ◽  
pp. 1054-1057
Author(s):  
Xiang Zhang ◽  
Jin Liang Huang ◽  
Li Hua Li
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thioglycolic Acid ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zinc Blende ◽  
Transmission Electron ◽  
Fe Nanoparticles

ZnS: Cu/Fe nanocrystals were synthesized by hydrothermal method with thioglycolic acid as a stabilizer. The phases, grain size and luminescent properties of the nanocrystals were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and fluorescence photometer respectively. The results showed that ZnS: Cu/Fe nanoparticles have a particle size about 7nm and possess a cubic zinc blende crystal structure. The luminous intensity of ZnS: Cu/Fe nanocrystals was strongly when they were reacted at 140°C for 12 hours.

Hydrothermal Synthesis and Electrocatalytic Property for H2O2 Reduction of Co3O4 Nanocubes

2011 ◽  
Vol 311-313 ◽  
pp. 477-480
Author(s):  
Zhi Ai Yang ◽  
Li Jin Feng ◽  
Xia Wang ◽  
Rong Ma ◽  
Jian Ping Sun ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Process ◽  
Linear Sweep Voltammetry ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
Linear Sweep ◽  
Electrocatalytic Property ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Subscript textThe Co3O4 nanocubes were synthesized by hydrothermal process. The products are characterized in detail by multiform techniques: scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray analysis. The results show that the products are uniform nanocubes with an average crystallite size about 20-40 nm. Electrocatalytic property of the prepared Co3O4 nanocubes was characterized by linear sweep voltammetry. LSV results indicate that Co3O4 nanocubes exhibit a remarkable electrocatalytic activity for the H2O2 reduction.

Microwave Synthesis of Zirconia Nanoparticles

2008 ◽  
Vol 8 (8) ◽  
pp. 4159-4162 ◽  
Author(s):  
K. P. S. S. Hembram ◽  
G. Mohan Rao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Microwave Synthesis ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zirconium Acetate ◽  
Transmission Electron ◽  
Zirconia Nanoparticles ◽  
Scanning Electron

Zirconia nanoparticles were prepared by microwave synthesis from zirconium acetate hydroxide. The samples were characterized by various techniques like X-ray diffraction (XRD), Scanning Electron microscopy (SEM), Transmission Electron microscopy (TEM), Raman Spectroscopy (RS). By XRD the average crystallite size is obtained around 10 nm and which is comparable to observation by SEM and TEM.

Synthesis and Luminescence Properties of Yb3+/Ho3+ Co-Doped Lu2O3 Nanocrystalline Powders

2007 ◽  
Vol 280-283 ◽  
pp. 521-524
Author(s):  
Li Qiong An ◽  
Jian Zhang ◽  
Min Liu ◽  
Sheng Wu Wang
Keyword(s):  
Electron Microscopy ◽  
Upconversion Luminescence ◽  
Nanocrystalline Powders ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Co Doped

Yb3+ and Ho3+ co-doped Lu2O3 nanocrystalline powders were synthesized by a reversestrike co-precipitation method. The as-prepared powders were examined by the X-ray diffraction and transmission electron microscopy. The phase composition of the powders was cubic and the particle size was in the range of 30~50 nm. Emission and excitation spectra of the powders were measured by a spectrofluorometer and the possible upconversion luminescence mechanism was also discussed.

Simplified Synthesis and Luminous Mechanism of Eu2+-Doped α-Si3N4 Nanowires with Strong Green Luminescent Properties

2017 ◽  
Vol 727 ◽  
pp. 635-641 ◽  
Author(s):  
Rui Su ◽  
Zhi Feng Huang ◽  
Fei Chen ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Broad Band ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Broad Band Emission ◽  
Band Emission ◽  
Nitridation Process ◽  
Transmission Electron

Ultra-long, single crystal, Eu-doped α-Si3N4 nanowires were prepared by a simple approach involving nitriding Eu-doped cryomilled nanocrystalline Si powder in NH3 flow at 1350 °C for 4 h. Phases, chemical composition and microcosmic feature of cryomilled powders and as-prepared nanowires were tested by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), respectively. The results suggested that Eu was successfully introduced into Si lattice after the cryomilling process and then entered into the lattice of α-Si3N4 during the nitridation process. The as-synthesized Eu-doped α-Si3N4 nanowires had highly uniform dimension with 20~30 nm in diameter and ~100 μm in length. The room temperature photoluminescence (PL) spectrum of as-synthesized nanowires showed a broad band emission center at 570 nm which was attributed to the transition from 4f65d to 4f7 in Eu2+. The transition from Eu3+ to Eu2+ during nitridation process was tested by X-ray photoelectron spectroscopy (XPS).

Fabrication of Pd-Doped SiO2 Aerogels by Radiation Method

2016 ◽  
Vol 847 ◽  
pp. 308-312
Author(s):  
Ming Long Zhong ◽  
Chao Yang Wang ◽  
Zhi Bing Fu ◽  
Yong Zeng ◽  
Qi Fang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Textural Properties ◽  
Pd Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Radiation Method ◽  
Surface Areas ◽  
Transmission Electron ◽  
Scanning Electron

The radiation method was studied to prepare Pd-doped SiO2 aerogels with different contents. The textural properties of the pristine SiO2 aerogels and Pd-doped SiO2 aerogels were systematically characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and N2 adsorption measurements. It can be concluded that there were large amounts of Pd particles presented in the framework of SiO2 aerogels after radiation. In addition, the size of Pd particles increased with the increase of radiation dose. The introduction of Pd nanoparticles produced a reduction of the surface areas, total pore and mesopore volumes.

Microstructure of Ti6Al4V after Ultrasound-Aided Deep Rolling

2013 ◽  
Vol 661 ◽  
pp. 141-144
Author(s):  
Li Li ◽  
Zhen Yu Fu ◽  
Tao Li ◽  
Jin Jun Liu ◽  
Zheng Yu Tian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Microstructure ◽  
Deep Rolling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ti6al4v Titanium Alloy ◽  
Transmission Electron ◽  
20 Nm ◽  
Scanning Electron

Ti6Al4V titanium alloy was treated by an ultrasound-aided deep rolling (UADR) process. The microstructure of UADR treated specimen was observed via using scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Results show that ultrasound-aided deep rolling produced nanocrystallized microstructure of grain scale typically less than 20 nm on the immediate surface of Ti6Al4V. A nanometer to submicron gradient structured layer penetrating to a depth of about 150 μm was formed after UADR treatment. The above improvements of surface microstructure of the UADR treated specimen is believed to be beneficial to its anti-fatigue performance.

The Effects of Temperature of Hydrothermal Growth of Titanium Dioxide Nanomaterial

2012 ◽  
Vol 545 ◽  
pp. 93-99
Author(s):  
Ahmad Anis Kalantar Mastan ◽  
Muti Mohamed Norani ◽  
Sharizal Shaik Ahmedullah
Keyword(s):  
Electron Microscopy ◽  
Titanium Dioxide ◽  
Surface Morphology ◽  
Sodium Hydroxide Solution ◽  
Hydrothermal Growth ◽  
X Ray Diffraction ◽  
Average Width ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm

Titanium dioxide (titania) nanomaterials have been extensively studied for various applications including gas sensor [1], dye-sensitized solar cell [2] and photocatalyst [3]. Titania nanomaterials can be produced using various methods depending on the desired surface morphology. As such the optimization of methods is the key to produce nanomaterials with desired properties where the study here focuses on the effect of autoclaving temperature for the hydrothermal growth. Titania P25 (Degussa, Germany) in 5 M sodium hydroxide solution (NaOH) was treated hydrothermally for 24 hours at 100 °C, 120 °C, 150 °C and 170 °C. Hydrothermal treatment for 24 hours at 150 °C produced nanotubes and treatment at 170 °C produces nanowires. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) were performed to study the surface and internal morphology of nanomaterials formed. Nanowires produced are of average width of 20 nm and length of 200 nm to 1 µm. Nanotubes produced are average width of 25 nm consisting of multiple walls. Varying the autoclaving temperature will affect the surface morphology of nanomaterials; forming nanotubes at 150 °C and nanowires at 170 °C. Understanding the effect of the process temperature would allow for optimization of the process in order to produce titania nanomaterial with specific characteristics that exhibit enhanced functionality for the development of their applications.

Nanostructured red-emitting MgGa2O4:Eu3+ phosphors

2004 ◽  
Vol 19 (5) ◽  
pp. 1504-1508 ◽  
Author(s):  
Bin-Siang Tsai ◽  
Yen-Hwei Chang ◽  
Yu-Chung Chen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sol Gel ◽  
Photoluminescence Intensity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Gel Technique ◽  
Red Luminescence ◽  
20 Nm

Nano-grained phosphors of Eu3+-doped MgGa2O4 crystallites were prepared by sol-gel technique. The characterization and optical properties of luminescent MgGa2O4:Eu3+ powders have been investigated. The dried sol-gel powders were calcined in air at different temperature from 600 to 1000 °C for 5 h. The x-ray diffraction profiles showed that the MgGa2O4:Eu3+ powders began to crystallize around 600 °C and formed stable MgGa2O4 phase in the temperature range of 600–900 °C. The transmission electron microscopy morphology observations revealed that the fired powders exhibit small grain size less than 20 nm. In the PL studies, under ultraviolet (394 nm) excitation, the calcined powders emitted bright red luminescence (615 nm, 5D0→7F2), and the powders fired at 900 °C were found to have the maximum photoluminescence intensity. The quenching concentration of Eu3+ in MgGa2O4 crystallites was also indicated to be about 5∼6 mol%.

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