scholarly journals Luminescence Performance of Yellow Phosphor SrxBa1−xTiO3: Eu3+, Gd3+for Blue Chip

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Limin Dong ◽  
Jian Li ◽  
Qin Li ◽  
Lianwei Shan ◽  
Zhidong Han
Keyword(s):  
Light Emission ◽  
Solid Phase ◽  
Phase Method ◽  
Photoluminescence Excitation ◽  
X Ray Diffraction ◽  
Yellow Light ◽  
X Ray ◽  
Potential Applications ◽  
Solid Phase Method ◽  
Luminescence Performance

The SrxBa1−xTiO3: Eu3+, Gd3+phosphors are synthesized by high temperature solid-phase method. Multiple techniques including X-ray diffraction (XRD), and scanning electron microscopy (SEM) are used to examine the surface morphology and structural properties of SrxBa1−xTiO3: Eu3+, Gd3+phosphors. The optical properties are presented and discussed in terms of photoluminescence (PL) and photoluminescence excitation (PLE) spectra. The as-obtained SrxBa1−xTiO3: Eu3+, Gd3+phosphors show higher PL emission intensity (at 591, 611 nm). The peaks at 591 and 611 nm are attributed to Eu3+  5D0-7F1,5D0-7F2. Gd3+has a strong sensitization on Eu3+. A certain amount of Sr2+and Ba2+is contributed to the intensity of light emission. After being irradiated with blue light, the phosphor samples emit yellow light. This suggests its potential applications in many fields.

Solubility of Mn in ZnO Crystallites Synthesized Using Solid State Techniques

2020 ◽  
Vol 3 (1) ◽  
pp. 28-39
Author(s):  
Esau Nii Abekah Akwetey Armah ◽  
Martin Egblewogbe ◽  
Hubert Azoda Koffi ◽  
Alfred Ato Yankson ◽  
Francis Kofi Ampong ◽  
...  
Keyword(s):  
Solid Phase ◽  
Solubility Limit ◽  
Phase Method ◽  
Regular Pattern ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Samples ◽  
Solid Phase Method ◽  
Mn Concentration

Powder samples of Zn1-xMnxO nanocrystal were synthesized at a temperature of 200 °C using solid phase method. Dopant concentrations of 0.005 ≤ x ≤ 0.5 were studied. Powder x-ray diffraction (PXRD) patterns of the samples were analyzed with a view of determining the onset of secondary phases, hence the solubility limit of the dopant. The solubility limit for Mn in ZnO samples synthesized at 200 °C is realized at x < 0.3. With a regular pattern in increment of the Mn concentration, there were variations observed in the trend of the relative intensity, 2θ position and d-spacing indicating uneven addition of Mn (thus Mn2+, Mn3+ or Mn4+).

scholarly journals Facile Synthesis of Mn0.68Bi0.32OCl Mix-Crystals And Its Supercapacitive Behavior

2021 ◽  
Author(s):  
Y.Z. Song ◽  
B.X. Qi ◽  
M.T. Li ◽  
J.M. Xie
Keyword(s):  
Surface Area ◽  
Solid Phase ◽  
Life Time ◽  
Molar Ratio ◽  
Phase Method ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Solid Phase Method

Abstract Mn0.68Bi0.32OCl mix-crystals for supercapacitor were successfully synthesized via a facile solid-phase method using Bi(NO3)3 and MnCl2 with molar ratio of 1:1 as precursors. The Mn0.68Bi0.32OCl mix-crystals were characterized by scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller surface area measurements and thermogravimetry and differential scanning calorimetry, respectively. Cyclic voltammetry and galvanostatic charge/discharge technique were performed for the Mn0.68Bi0.32OCl mix-crystals in 1 M Na2SO4 aqueous solutions; the specific capacitance of Mn0.68Bi0.32OCl was about 203 F.g-1 at the current density of 3 A. g-1 with a long life time, owing to the high power density of Mn0.68Bi0.32OCl mix-crystals and the higher surface area, good conductivity, and high stability of the Mn0.68Bi0.32OCl mix-crystals.

Combustion Synthesis of La0.65Sr0.35MnO3 and its Sensing Properties for NO2

2016 ◽  
Vol 680 ◽  
pp. 208-211
Author(s):  
Lian Lian Wu ◽  
Qiang Li ◽  
Dan Yu Jiang ◽  
Jin Feng Xia
Keyword(s):  
Solid Phase ◽  
High Sensitivity ◽  
Combustion Method ◽  
Fast Response ◽  
Size Analysis ◽  
Phase Method ◽  
X Ray Diffraction ◽  
Ultrafine Structure ◽  
Nox Sensor ◽  
Solid Phase Method

In this paper, La0.65Sr0.35MnO3 (LSM) oxide powder with ultrafine structure has been synthesized by self-propagating combustion method. The powders were characterized by X-ray diffraction, scanning electron microscopy and laser size analysis. Compared to the powders prepared by traditional solid-phase method, the grain size of powders prepared by self-propagating combustion method is relatively small and uniform. Starting from ultrafine LSM powders, sensing electrode (SE) for NO2 mixed-potential sensors based on yttria-stablized zirconia (YSZ) was fabricated. As-obtained NO2 sensor displays fast response and high sensitivity (25.4mV/decade). The response values of the sensor have good linear relationship with the logarithm of NO2 concentration varying from 30ppm to 500ppm.Keywords:Self-propagating combustion method; La0.65Sr0.35MnO3; NOx sensor; YSZ

Synthesis and properties of double gadolinium tellurites

2021 ◽  
Vol 103 (3) ◽  
pp. 67-73
Author(s):  
A.A. Toibek ◽  
◽  
K.T. Rustembekov ◽  
D.A. Kaikenov ◽  
M. Stoev ◽  
...  
Keyword(s):  
Phase Analysis ◽  
Solid Phase ◽  
Heat Capacities ◽  
Ceramic Technology ◽  
Phase Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Temperature Range ◽  
Diffraction Patterns

For the first time, double gadolinium tellurites of the composition GdMIITeO4.5 (MII — Sr, Ba) were synthesized by the solid-phase method. The solid-phase synthesis of samples was carried out from decrepitated gadolinium (III) and tellurium (IV) oxides, strontium, and barium carbonates according to the standard ceramic technology. The synthesis was carried out in the temperature range of 800-1100 °C. The samples obtained were confirmed by X-ray phase analysis. X-ray phase analysis was carried out on an Empyrean instrument in the XRDML Pananalitical format. The intensity of the diffraction maxima was estimated on a 100-point scale. X-ray diffraction patterns indexing of the powder of gadolinium tellurites — alkaline earth metals studied were carried out by the homology method. The reliability and correctness of the results of indexing the X-ray diffraction patterns are confirmed by the good agreement between the experimental and calculated values of the interplanar distances (d) and the agreement between the values of the X-ray and pycnometric densities. It was found that compounds GdSrTeO4.5 and GdBaTeO4.5 crystallize in the monoclinic system and have the unit cell parameters, namely GdSrTeO4.5 — a = 12.7610, b = 10.4289, c = 8.6235 Å, V° = 1141.83 Å3, β = 95.77°, Z = 5, ρrent. = 3.22, ρpikn. = (3.10±0.09) g/cm3; GdBaTeO4.5 — a = 15.7272, b = 15.8351, c = 7.1393 Å, V° = 1769.72 Å3, β = 95.53°, Z = 8, ρrent = 3.71, ρpick = (3.61±0.10) g/cm3. Using the Landiya method, the standard heat capacities of the compounds were estimated from the calculated values of the standard entropies, and the temperature dependences of the heat capacities of the gadolinium tellurites synthesized were determined in the temperature range of 298–850 K.

PHOTOLUMINESCENCE OF NON-CRYSTALLINE ALUMINA NANOWIRES SYNTHESIZED BY DIRECT ANODIZATION OF ALUMINUM

2009 ◽  
Vol 23 (14) ◽  
pp. 1819-1825
Author(s):  
JAYA SARKAR ◽  
GOBINDA GOPAL KHAN ◽  
A. BASUMALLICK
Keyword(s):  
Light Emission ◽  
Pure Aluminum ◽  
Bath Temperature ◽  
Constant Current ◽  
X Ray Diffraction ◽  
Constant Current Density ◽  
X Ray ◽  
Anodization Process ◽  
Potential Applications ◽  
Crystalline Alumina

Alumina nanowires have been synthesized by a simple electrochemical route, by tailoring the anodization process of aluminum. Two-stage anodization of pure aluminum foils were carried out in 0.3 M oxalic acid electrolyte by maintaining a constant current density of 250 A/m2 and suitably controlling the other anodization parameters: anodization voltage, bath temperature and anodization time. The fabricated alumina nanowires were investigated by field-emission scanning electron microscope (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). Moreover, the X-ray diffraction (XRD) study on the prepared nanowires shows that they are non-crystalline in nature. The photoluminescence (PL) spectra of alumina nanowires exhibit two stable emission bands at 438 and 581 nm. The blue luminescence behavior of the alumina nanowires are attributed to the oxygen-deficient defect centers. PL study of alumina nanowires shows that they have potential applications in light emission devices.

scholarly journals Enhanced Electrochemical Performances of Cobalt-Doped Li2MoO3 Cathode Materials

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 843 ◽  
Author(s):  
Zhiyong Yu ◽  
Jishen Hao ◽  
Wenji Li ◽  
Hanxing Liu
Keyword(s):  
Cathode Materials ◽  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Phase Method ◽  
Electrochemical Performances ◽  
X Ray ◽  
Electrochemical Tests ◽  
Co Doping ◽  
Solid Phase Method ◽  
Better Than

Co-doped Li2MoO3 was successfully synthesized via a solid phase method. The impacts of Co-doping on Li2MoO3 have been analyzed by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) measurements. The results show that an appropriate amount of Co ions can be introduced into the Li2MoO3 lattices, and they can reduce the particle sizes of the cathode materials. Electrochemical tests reveal that Co-doping can significantly improve the electrochemical performances of the Li2MoO3 materials. Li2Mo0.90Co0.10O3 presents a first-discharge capacity of 220 mAh·g−1, with a capacity retention of 63.6% after 50 cycles at 5 mA·g−1, which is much better than the pristine samples (181 mAh·g−1, 47.5%). The enhanced electrochemical performances could be due to the enhancement of the structural stability, and the reduction in impedance, due to the Co-doping.

scholarly journals Structural properties of TiO2-SnO2 thin films prepared by new pyrolysis solid-phase method

2021 ◽  
Vol 2086 (1) ◽  
pp. 012042
Author(s):  
M G Volkova ◽  
V Yu Storozhenko ◽  
V V Petrov ◽  
E M Bayan
Keyword(s):  
Solid Phase ◽  
Sem Analysis ◽  
Phase Method ◽  
Materials Properties ◽  
X Ray ◽  
Synthesis Parameters ◽  
Solid Phase Method ◽  
Sno2 Thin Films ◽  
Low Temperature Pyrolysis ◽  
Synthesized Materials

Abstract Nanoscale TiO2-SnO2 films with the Ti:Sn ratio 1:99, 3:97 and 5:95 mol%, respectively, were obtained by solid-phase low-temperature pyrolysis method. The synthesized materials were studied by X-ray phase analysis and scanning electron microscopy (SEM) analysis. Regardless of the modified agents’ concentration, the structure of cassiterite was observed for all synthesized materials. When studying the effect of synthesis parameters on the materials properties, it was shown that both an increase in the Ti4+ concentration and in the calcination temperature leads to an increase in the particle size.

Influence of Titanium Ion Doped Amount on the Dielectric Property of BMNT Ceramics

2013 ◽  
Vol 760-762 ◽  
pp. 772-775
Author(s):  
Xin You Huang ◽  
Yuan Zuo ◽  
Chun Hua Gao
Keyword(s):  
Dielectric Property ◽  
Solid Phase ◽  
Pyrochlore Phase ◽  
Volume Density ◽  
Phase Method ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Solid Phase Method ◽  
Ceramic Density ◽  
Sintered Temperature

Bi2(Mgl/3Nb2/3-xTix)2O7(BMNT)(x=0.1, 0.15, 0.2, 0.25) ceramics was prepared by conventional solid phase method, The influence of titanium ion doped amount on the dielectric property and microstructure of BMNT ceramics were systematically studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and other testing and analysis how to methods. Results show that there is single monoclinic pyrochlore phase and there is not the second phase in all BMNT ceramics doped with titanium ion. The grain size of BMNT ceramics increases first and then decreases, the dielectric constant (εr) increases first and then decreases, the dielectric loss (tanδ) increases first and then decreases, the ceramic density decreases all the time while titanium ion doped amount increases. The ceramic density increases first and then decreases when sintered temperature increases. The density of BMNT ceramics doped with titanium ion is biggest when sintered temperature is 980 °C. When sintered temperature is 980 °C and titanium ion doped amount is 0.15mol, the dielectric properties of BMNT ceramics is good,which εris 135(1MHz), tanδ is 0.002(1MHz) and volume density is 7.46g/cm3.

Structure and Optical Thermometry Characterization of Er3+/Yb3+ Co-Doped BaGd2CuO5

2016 ◽  
Vol 16 (4) ◽  
pp. 3542-3546 ◽  
Author(s):  
Xiaodong Li ◽  
Yanjie Song ◽  
Yanmin Yang ◽  
Chao Mi ◽  
Yanzhou Liu ◽  
...  
Keyword(s):  
Solid Phase ◽  
Green Emission ◽  
Upconversion Emission ◽  
Phase Method ◽  
Excitation Density ◽  
Fluorescence Intensity Ratio ◽  
X Ray Diffraction ◽  
Solid Phase Method ◽  
Fir Technique ◽  
Co Doped

Er3+/Yb3+ co-doped BaGd2CuO5 upconversion luminescent materials are obtained by solid phase method. Rietveld refinement on X-ray diffraction data indicates that Er3+/Yb3+ ions are inclined to occupy the Gd(1) site in the structure of BaGd2CuO5 (green phase). Two green emission peaks located at 523 nm and 547 nm have been produced by the excitation of 971 nm LD. The fluorescence intensity ratio (FIR) of the two green emission peaks have been investigated in the temperature range of 290 K–594 K. The maximum sensitivity derived from the FIR technique of the green upconversion emission is approximately 0.0038 K−1, and it has a high transmission power at low excitation density. This result implies that the Er3+/Yb3+ co-doped BaGd2CuO5 phosphors can play an important role in temperature measurements with a better sensitivity.

scholarly journals Effect of Li+ doping on the luminescence performance of a novel KAlSiO4:Tb3+ green-emitting phosphor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Reziwanguli Yantake ◽  
Muyasier Kaiheriman ◽  
Taximaiti Yusufu ◽  
Aierken Sidike
Keyword(s):  
Solid Phase ◽  
Diffuse Reflectance Spectrum ◽  
Green Light ◽  
Phase Method ◽  
Excellent Thermal Stability ◽  
Yield Increase ◽  
Li Doping ◽  
Silicate Phosphor ◽  
Solid Phase Method ◽  
Luminescence Performance

AbstractA new green-emitting phosphor, KAlSiO4:1.5 mol% Tb3+, x mol% Li+, was prepared via a high-temperature solid-phase method, and its crystal structure, diffuse reflectance spectrum, and luminescence were studied. The results show that the Li+ doping shifts the strongest diffraction peak to a high angle direction, reducing grain size by 11.4%. The entry of Li2CO3 improves the luminescence performance of KAlSiO4:1.5 mol% Tb3+. At a Li+ concentration of 1.5 mol%, the sample has strong absorption in the ultraviolet light range from 250 to 400 nm. The luminous intensity of the sample at 550 nm approximately quadruples after Li+ doping. Additionally, the colour purity of the sample and the internal quantum yield increase to 83.3% and 42%, respectively. The sample changes colour with time when exposed to air without an obvious fading phenomenon. The emission intensity at 200 °C is 95.1% of its value at room temperature, indicating that the phosphor has excellent thermal stability when x = 1.5. These results show the feasibility of using the silicate phosphor for generating the green light component of white light-emitting diodes for solid-state lighting.

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