Influences of Reaction Conditions on the Morphology and Properties of CaWO4 Films Prepared by Anodization

2014 ◽  
Vol 809-810 ◽  
pp. 654-659
Author(s):  
Jian Ling Zhao ◽  
Yong Liao ◽  
Li Ye Zhao ◽  
Xiao Jing Yang ◽  
Wei Yu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Photoluminescence Intensity ◽  
Constant Voltage ◽  
Photoluminescence Properties ◽  
Reaction Conditions ◽  
X Ray ◽  
Anodization Method ◽  
Scanning Electron

CaWO4 films were prepared in saturated Ca(OH)2 solution through constant-voltage anodization method. Influences of reaction time, voltage and temperature on the morphology, crystal structure and photoluminescence properties were studied through scanning electron microscopy (SEM), X-ray diffractometer (XRD) and photoluminescence measurements (PL). Results show that the as-prepared CaWO4 film is of tetragonal phase, the reaction conditions affect the morphology, grain size and photoluminescence properties greatly. The CaWO4 film anodized at 20V, 45°C for 40 min is flat, uniform and dense with stronger photoluminescence intensity. The formation process of CaWO4 films has also been discussed.

SYNTHESIS, MORPHOLOGY AND STRUCTURAL PROPERTIES OF (GD,ND)SR2RUCU2O8 SAMPLES

2003 ◽  
Vol 17 (04n06) ◽  
pp. 899-904 ◽  
Author(s):  
A. VECCHIONE ◽  
M. GOMBOS ◽  
C. TEDESCO ◽  
A. IMMIRZI ◽  
L. MARCHESE ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
X Ray ◽  
Structure And Morphology ◽  
Polycrystalline Powder ◽  
Scanning Electron

NdSr 2 RuCu 2 O x material has been prepared as polycrystalline powder by solid state reaction. The compound has been investigated by synchrotron x-ray powder diffraction and scanning electron microscopy. The experimental results show that the average crystal structure is a disordered cubic perovskite with Nd and Sr cations occupying the same site and the same substitution is found for Cu and Ru atoms. A comparison between the crystal structure and morphology of this compound and the superconducting tetragonal GdSr 2 RuCu 2 O 8 is also discussed.

Crystal Structure of BiFeO3 Synthesized Using the Hydrothermal Processing

2014 ◽  
Vol 602-603 ◽  
pp. 947-950
Author(s):  
Zhen Wang ◽  
Hai Yan Chen ◽  
Lin Qiang Gao ◽  
Xin Zou
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Single Phase ◽  
Hydrothermal Processing ◽  
Optimal Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

BiFeO3 nanoparticles were successfully synthesized by a hydrothermal method by a mineralizer (KNO3). Structural characterization was performed by thermal analysis, powder X-ray diffraction (XRD) and scanning electron microscopy (TEM).The results showed that the products were perovskite structure BiFeO3 powders. Optimal conditions for the synthesis of single-phase BiFeO3 ceramics were obtained.

scholarly journals Synthesis and photoluminescence properties of Ba2Y3(SiO4)3F:Tm3+ blue-emitting fluorosilicate phosphors

2020 ◽  
Vol 185 ◽  
pp. 04051
Author(s):  
Junhui Yang ◽  
Huanyou Wang ◽  
Jinhua Liu ◽  
Jun Chen ◽  
Fanhua Zeng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Concentration Quenching ◽  
Photoluminescence Properties ◽  
Quenching Mechanism ◽  
Multipole Interaction ◽  
Phase Purity ◽  
X Ray ◽  
Chromaticity Coordinates ◽  
Scanning Electron

Various novel Ba2Y3(SiO4)3F:Tm3+ blue-emitting fluorosilicate materials were achieved via solid-state synthesis. The structure and phase purity of prepared Ba2Y3(SiO4)3F:xTm3+ (x = 0.001-0.10 mol) were examined by X-ray powder diffraction. The surface morphology of Ba2Y3(SiO4)3F:0.01Tm3+ was studied by scanning electron microscopy. Photoluminescence properties were systematically explored under the monitoring emission (λem = 468 nm) and excitation (λex = 302 nm) spectra. The optimum mole ratio of as-synthesized phosphors was 0.01 mol. The concentration quenching mechanism in the Ba2Y3(SiO4)3F host was due to electric multipole interaction. Particularly, the chromaticity coordinates (0.1334, 0.0474) of Ba2Y3(SiO4)3F:0.01Tm3+ are near to those of the commercial BaMgAl10O17:Eu2+. These results validated the Ba2Y3(SiO4)3F:Tm3+ fluorosilicate phosphor can be used as a good blue-emitting candidate for W-LEDs.

Identification of Several New Ferromagnetic and Antiferromagnetic Rare Earth Cuprates

1990 ◽  
Vol 48 (2) ◽  
pp. 498-499
Author(s):  
M. Fendorf ◽  
S.W. Keller ◽  
A.M. Stacy ◽  
R. Gronsky
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Rare Earth ◽  
Magnetic Behavior ◽  
Chemical Form ◽  
The Other ◽  
X Ray ◽  
Scanning Electron ◽  
The Eu

Several new rare earth cuprates having the chemical form RxCuyOz (where R represents the rare earths La, Nd, Sm, Eu, and Gd) have recently been synthesized using a NaOH flux at 400°C. The materials are polycrystalline, and contain varying amounts of R2CuO4 and CuO. During subsequent susceptibility measurements using a SQUID magnetometer, it was found that the Gd material orders antiferromagnetically at approximately 14K, while the other compounds become ferromagnetic between 18K and 28K. Treatment of the powders with 12M HC1 for several minutes dissolves the impurity R2CuO4 and CuO phases, thus facilitating efforts to determine the composition and crystal structure of the new ferromagnetic and antiferromagnetic cuprates. Details of synthesis and magnetic behavior of these materials are to be published elsewhere. In this study, a first attempt is made to characterize the Eu and Gd materials.Energy dispersive x-ray analysis carried out during scanning electron microscopy work indicates that the R:Cu ratio in the Gd material is 1:1.70 (close to 3:5) and that in the Eu material is 1:1.96 (close to 1:2).

Synthesis and Photoluminescence of Rhombic NaLa(MoO4)2:Ln3+ Nanocrystals

2016 ◽  
Vol 16 (4) ◽  
pp. 3617-3621 ◽  
Author(s):  
Yuping Wang ◽  
Mingxia Li ◽  
Kai Pan ◽  
Rong Li ◽  
Naiying Fan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Luminescence Intensity ◽  
Dopant Concentration ◽  
Emission Spectra ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Rhombic NaLa(MoO4)2:Ln3+ (Ln = Eu and Tb) nanocrystals were synthesized by a hydrothermal method. The structures and morphologies of the nanocrystals were characterized by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The results indicated that the crystalline size increased with increasing Na2MoO4 content. The photoluminescence properties of NaLa(MoO4)2:Ln3+ nanocrystals were investigated in detail. In the emission spectra of NaLa(MoO4)2:Eu3+ nanocrystals, the 5D0 → 7F2 is dominant, and the peak positions and spectral shapes of emissions were independent of Eu3+ concentration. The luminescence intensity increased with increasing Eu3+ concentration, up to about 10 mol%, and then decreased. In the emission spectra of NaLa(MoO4)2:Tb3+ nanocrystals, the 5D4 → 7F5 is dominant. The sample with a dopant concentration of 20 mol% showed the highest emission intensity.

scholarly journals Synthesis, Crystal Structure Refinement, and Electrical Conductivity of Pb(8−x)Na2Smx(VO4)6O(x/2)

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Tatiana M. Savankova ◽  
Lev G. Akselrud ◽  
Lyudmyla I. Ardanova ◽  
Alexey V. Ignatov ◽  
Eugeni I. Get’man ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Solid Solutions ◽  
Structure Refinement ◽  
Crystal Structure Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Solid solutions of Pb(8−x)Na2Smx(VO4)6O(x/2)were studied using X-ray diffraction analysis including Rietveld refinement and scanning electron microscopy and by measuring their electrical conductivity. Crystal structure of the solid solutions was refined and the solubility region0≤x≤0.2was determined for samarium substitution for lead under the scheme2Pb2++□→2Sm3++O2-. The influence of degree of substitution on the electrical conductivity of solid solutions was established.

The Effect of the Distribution of Ag in High TC Bi- Compound Superconductors

1989 ◽  
Vol 169 ◽  
Author(s):  
Alexis S. Nash ◽  
K. C. Goretta ◽  
Philip Nash ◽  
R. B. Poeppel ◽  
Donglu Shi
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solid State ◽  
Energy Dispersive Spectrometry ◽  
Temperature Data ◽  
Energy Dispersive ◽  
High Tc ◽  
X Ray ◽  
Scanning Electron

AbstractA series of 4336 Bi‐Sr‐Ca‐Cu oxide samples doped with 1 to 5% metallic Ag was prepared by solid state reaction. The distribution of Ag, the microstructure and the crystal structure of the samples were studied using energy dispersive spectrometry, EDS, scanning electron microscopy, SEM, and x‐ray diffractometry, XRD. Addition of Ag leads to a marked increase in preferred orientation with (001) planes perpendicular to the pressing direction in sintered pellets. The resistivity‐temperature data show an enhanced Tc in Ag‐doped samples under certain conditions. Energy dispersive spectrometry indicates that the dopant mostly segregates to the grain boundaries.

scholarly journals Preparation and luminescence properties of Tm3+-doped SrBi2Ta2O9 blue-emitting phosphor

2021 ◽  
Vol 261 ◽  
pp. 02080
Author(s):  
Jianhua Li ◽  
Jinyu Huang ◽  
Jing Liao ◽  
Jinjin Fu ◽  
Bin Deng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Concentration Quenching ◽  
Photoluminescence Properties ◽  
Quenching Mechanism ◽  
Multipole Interaction ◽  
Phase Purity ◽  
X Ray ◽  
Chromaticity Coordinates ◽  
Scanning Electron

Various novel SrBi2Ta2O9:Tm3+ blue-emitting materials were achieved via solid-state synthesis. The structure and phase purity of prepared SrBi2Ta2O9:xTm3+ (x = 0.005-0.30 mol) were examined by X-ray powder diffraction. The surface morphology of SrBi2Ta2O9:0.01Tm3+ were studied by scanning electron microscopy. Photoluminescence properties were systematically explored under the monitoring emission (λem = 468 nm) and excitation (λex = 303 nm) spectra. The optimum mole ratio of as-synthesized phosphors was 0.01 mol. The concentration quenching mechanism in the SrBi2Ta2O9 host was due to electric multipole interaction. Particularly, the chromaticity coordinates (0.1334, 0.0474) of SrBi2Ta2O9:0.01Tm3+ are near to those of the commercial BaMgAl10O17:Eu2+. These results validated the SrBi2Ta2O9:Tm3+ phosphor can be utilized good blue-emitting candidate for W-LEDs.

Study on the Properties of Poplar Micro/Nanofibril and its Composites

2012 ◽  
Vol 621 ◽  
pp. 48-53
Author(s):  
Yan Ping Liu ◽  
Jiang Tao Zhang ◽  
Xiao Ya Luo ◽  
Ying Ying Yao
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wheat Straw ◽  
Internal Bond ◽  
Urea Formaldehyde ◽  
Formaldehyde Resin ◽  
Chemical Compositions ◽  
X Ray ◽  
Scanning Electron

The micro/nanofibrils of poplar could be prepared by treatment of ultrasonic. The properties of micro/nanofibrils were characterized by using scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The results indicated that poplar micro/nanofibril was the same as raw fiber in chemical compositions and crystal structure. The crystallinity of micro/nanofibrils was 84.99 percent, increased by 20 percent compared to original fiber after ultrasonic crushing. The micro/nanofibril diameter was from 50 nm to 1 μm.The internal bond strength (IB) of wheat-straw fiberboard could be significantly improved by adding poplar micro/nanofibril suspension to the urea formaldehyde resin adhesive(UF),when the adding amount of poplar micro/nanofibril suspension was 15wt percent, the IB of wheat-straw fiberboard was up to 0.86 MPa.

Study of Synthesis and Crystal Structure of Barium Cerate at High Temperatures

2017 ◽  
Vol 891 ◽  
pp. 473-477
Author(s):  
Renáta Verbová ◽  
Viktor Kavečanský ◽  
Pavel Diko ◽  
Samuel Piovarči
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Barium Cerate ◽  
X Ray Diffraction ◽  
Oxalate Precursor ◽  
X Ray ◽  
Different Temperatures ◽  
Average Size ◽  
Scanning Electron

Crystalline barium cerate was synthesized by oxalate coprecipitation from nitrates of barium and cerium [1]. The oxalate precursor prepared by chemical methods was calcined at different temperatures up to 950°C. The barium cerate was studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). X-ray diffraction investigation enables the determination of the phases that originate at different stages of synthesis and the crystal structure of final barium cerate, as well. From XRD patterns the average size of coherent regions was estimated by using Halder-Wagner method [2]. Both size and shape of crystallites were also studied by scanning electron microscopy. It was found that crystallites of barium cerate arise within the initial particles of the oxalate precursor.

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