Synthesis and Upconversion Luminescence of Water-Soluble of GdF3:Yb3+/Er3+ Nanoparticles

2016 ◽  
Vol 16 (4) ◽  
pp. 3981-3984 ◽  
Author(s):  
Gejihu De ◽  
B Asina ◽  
Wujiseleng Ma
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thermal Decomposition ◽  
Upconversion Luminescence ◽  
Green Emission ◽  
Water Soluble ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology

Water-soluble Yb3+/Er3+ doped GdF3 nanocrystals were prepared using a thermal decomposition synthesis route. The crystal structure, morphology and up-conversion spectra of the samples were characterized using X-ray powder diffractometry, transmission electron microscopy and a fluores- cence spectrophotometer with single-wavelength diode laser of 980 nm. In Yb3+- and Er3+-codoped GdF3 nanocrystals, the relative intensity of green emission became stronger as the sample changed from water-soluble nanoparticles to hexane-dispersed nanoparticles. The synthesis of such monidisperse, water-soluble, lanthanide-doped upconvertion particles will open new opportunities in targeting and drug delivery applications.

SINGLE STEP SYNTHESIS OF HYDROPHOBIC AND HYDROPHILIC NANOPARTICLES VIA THERMAL DECOMPOSITION

2011 ◽  
Vol 10 (04n05) ◽  
pp. 943-947 ◽  
Author(s):  
DIPAK MAITY ◽  
JUN DING
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thermal Decomposition ◽  
Single Step ◽  
Organometallic Complexes ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Here, we report single step synthesis of hydrophobic and hydrophilic Fe3O4 , ZnO , CoO and Y2O3:Eu nanoparticles via thermal decomposition of different organometallic complexes in oleylamine (OM) and tri(ethyleneglycol) (TREG) media, respectively. The crystal structure of the as-prepared nanoparticles is identified using X-ray diffraction, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Morphology of the nanoparticles is determined by transmission electron microscopy (TEM) while the magnetic properties are measured using vibrating sample magnetometer (VSM). Thermolysis of appropriate precursors in OM and TREG medium are very capable of producing the highly dispresed hydrophobic and hydrophilic nanoparticles with diverse morphologies.

Enhanced Red Upconversion Luminescence in Yb–Er Codoped NaYF4 Nanocrystals

2016 ◽  
Vol 16 (4) ◽  
pp. 3961-3964
Author(s):  
Weiye Song ◽  
Xueqing Bi ◽  
Xingyuan Guo ◽  
Shushen Liu ◽  
Weiping Qin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Upconversion Luminescence ◽  
Decomposition Reaction ◽  
Energy Transfer Mechanism ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Transmission Electron ◽  
Temperature Decomposition

In this work the effects of NaYF4:Yb, Er (NYE) structure on the enhanced red upconversion luminescence (UC) was investigated. -NYE nanocrystals (NCs) and -NYE NCs were fabricated by a high temperature decomposition reaction method. The prepared NCs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. The results show that the red UC luminescence of -NYE NCs is significantly enhanced compared with that of -NYE. Furthermore, a possible energy transfer mechanism was proposed on the basis of our experimental results.

Upconversion Luminescence Properties of NaYF4 Nanocrystals Precipitated Nd3+/Yb3+/Ho3+ Tri-Doped Oxyfluoride Glass Ceramics

2016 ◽  
Vol 16 (4) ◽  
pp. 3744-3748 ◽  
Author(s):  
Yuan Gao ◽  
Yuebo Hu ◽  
Dacheng Zhou ◽  
Jianbei Qiu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Transfer Process ◽  
Upconversion Luminescence ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Oxyfluoride Glass ◽  
X Ray ◽  
Transmission Electron ◽  
The Matrix

Transparent oxyflouride glass ceramics composed of SiO2–Al2O3–Na2O–NaF–YF3 tri-coped with Nd3+/Yb3+/Ho3+ were prepared by thermal treatment. Segregation of NaYF4 nanocrystals in the matrix was confirmed from structural analysis by means of X-ray diffraction and transmission electron microscopy. Compared with glass samples, very strong green upconversion (UC) luminescence due to the Ho3+:(4F5, 5S2)→5I8 transition was observed in the glass ceramics under 808 nm excitation. It was found that upconversion intensity of Ho3+ strongly depends on the Nd3+ concentration, and the energy transfer process from Nd3+ to Ho3+ via Yb3+ was proposed.

Lack of a threefold rotation axis in α-Fe2O3and α-Cr2O3crystals

2015 ◽  
Vol 71 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Michał Stękiel ◽  
Radosław Przeniosło ◽  
Izabela Sosnowska ◽  
Andrew Fitch ◽  
Jacek B. Jasiński ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rotation Axis ◽  
Magnetic Ordering ◽  
Evidence Based ◽  
Space Group ◽  
X Ray ◽  
Space Groups ◽  
Transmission Electron

The crystal structure of α-Fe2O3and α-Cr2O3is usually described with the corundum-type trigonal crystal structure based on the space group R\bar 3c. There are, however, some observations of the magnetic ordering of both α-Fe2O3and α-Cr2O3that are incompatible with the trigonal symmetry. We show experimental evidence based on X-ray powder diffraction and supported by transmission electron microscopy that the symmetry of the crystal structure of both α-Fe2O3and α-Cr2O3is monoclinic and it is described with the space groupC2/c(derived from R\bar 3c by removing the threefold rotation axis). The magnetic orderings of α-Fe2O3and α-Cr2O3are compatible with the magnetic space groupsC2/candC2/c′, respectively. These findings are in agreement with the idea from Curie [(1894),J. Phys.3, 393–415] that the dissymmetry of the magnetic ordering should be associated with a dissymmetry of the crystal structure.

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.

Synthesis and Magnetic Properties of CoFe2O4 Nano-Particles

2010 ◽  
Vol 148-149 ◽  
pp. 998-1002 ◽  
Author(s):  
Xiao Yun Chen ◽  
Hua Li ◽  
Yue Zeng Su ◽  
Zi Shan Huang ◽  
He Zhou Liu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Hydrothermal Process ◽  
Nano Particles ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Water Ratio

Spinel CoFe2O4 nano-particles were synthesized by hydrothermal traditionally and Ethylene Glycol (EG) assisted hydrothermal process originally. The effects of reaction temperatures from 140°C to 200°C, different OH- provider and EG/water ratio on the nano-particles’ structure, morphology and magnetic properties of composition were studied by X-ray diffractometer (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The possible mechanism for the effects on the properties was also discussed in details. The results showed that NaAC as OH- provider and higher EG/water ratio in solvent were benefit for getting smaller CoFe2O4 nano-particles. And existence of EG is also important to remove the α-Fe2O3 phase.

FABRICATION AND CHARACTERISTICS OF ALN NANOWIRES

2001 ◽  
Vol 15 (30) ◽  
pp. 1455-1458 ◽  
Author(s):  
H. CHEN ◽  
X. K. LU ◽  
S. Q. ZHOU ◽  
X. H. HAO ◽  
Z. X. WANG
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Sublimation Method ◽  
Scanning Electron

Single phase AlN nanowires are fabricated by a sublimation method. They were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), typical selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM). The SEM and TEM images show that most of the nanowires have diameters of about 10–60 nm. The crystal structure of AlN nanowires revealed by XRD, SAED and HRTEM shows the AlN nanowires have a wurtzite structure.

Prepare of the New Structure PbTiO3 Nanowires and the Study of the Reversible Bending

2013 ◽  
Vol 331 ◽  
pp. 522-526
Author(s):  
Jiang Wang ◽  
Jian Li ◽  
You Wen Wang
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stainless Steel ◽  
Hydrothermal Reaction ◽  
The Self ◽  
X Ray Diffraction ◽  
Electron Backscattered Diffraction ◽  
X Ray ◽  
Transmission Electron

When the self-made with Teflon lined with stainless steel reaction kettle is used to produce PbTiO3 nanowires with the adoption of hydrothermal reaction , PbTiO3 nanowires with new structure can be made when Pb/Ti equals 2.2. Observed through the Transmission Electron Microscopy (TEM), the bending feature of the PbTiO3 nanowires can be observed for several times when X-ray diffraction (XRD) and Electron Backscattered Diffraction (EBSD) are used to analyse and test the crystal structure of the nanowires. The result of the study shows that the degree of the bending of the PbTiO3 nanowires varies with the intensity of the electron beam from the Transmission Electron Microscopy, and its process can be reversible.

PHOTOLUMINESCENCE SPECTRA AND MAGNETIC PROPERTIES OF HYDROTHERMALLY SYNTHESIZED MnO2 NANORODS

2013 ◽  
Vol 27 (29) ◽  
pp. 1350211 ◽  
Author(s):  
ARBAB MOHAMMAD TOUFIQ ◽  
FENGPING WANG ◽  
QURAT-UL-AIN JAVED ◽  
QUANSHUI LI ◽  
YAN LI
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Blue Emission ◽  
Green Emission ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Uv Emission ◽  
Transmission Electron

In this paper, single crystalline tetragonal MnO 2 nanorods have been synthesized by a simple hydrothermal method using MnSO 4⋅ H 2 O and Na 2 S 2 O 8 as precursors. The crystalline phase, morphology, particle sizes and component of the as-prepared nanomaterial were characterized by employing X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and energy-dispersive X-ray spectroscopy (EDS). The photoluminescence (PL) emission spectrum of MnO 2 nanorods at room temperature exhibited a strong ultraviolet (UV) emission band at 380 nm, a prominent blue emission peak at 453 nm as well as a weak defect related green emission at 553 nm. Magnetization (M) as a function of applied magnetic field (H) curve showed that MnO 2 nanowires exhibited a superparamagnetic behavior at room temperature which shows the promise of synthesized MnO 2 nanorods for applications in ferrofluids and the contrast agents for magnetic resonance imaging. The magnetization versus temperature curve of the as-obtained MnO 2 nanorods shows that the Néel transition temperature is 94 K.

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