scholarly journals Band Gap Tailoring, Size Modulation and Photoluminescence Properties of Mn/Cu doped ZnS Nanostructures

2021 ◽  
Author(s):  
P.J. Binu ◽  
S. Muthukumaran
Keyword(s):  
Energy Gap ◽  
Effective Control ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
Cubic Structure ◽  
Diffraction Patterns ◽  
Co Precipitation ◽  
Band Gap Tailoring

Abstract ZnS, Mn added ZnS (Zn0.97Mn0.03S) and Mn, Cu dual doped ZnS (Zn0.95Mn0.03Cu0.02S) QDs have been prepared using co-precipitation technique. The influence of Mn and Cu addition on the morphology, structure and photoluminescence properties of Mn/Cu incorporated ZnS have been examined. Cubic structure of the synthesized samples was confirmed by X-ray diffraction patterns. The incorporation of Cu in Zn-Mn-S lattice not only decreased the particle/grain size and also generates more defect based luminescent activation centres. The reduced energy gap by Mn addition was explained by sp-d exchange interaction and the elevated energy gap in Cu, Mn dual doped ZnS was expalined by Burstein–Moss effect. The tuning phenomenon of size as well as the energy gap in ZnS by Mn/Cu addition promote these materials for nano-electronic applications. FTIR spectra confirmed the presence of Mn/Cr-Zn-S bondings. The substitution of Mn /Cu provides an effective control over tuning of different emission colours which signifies their applications like light emitting diodes.

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

The Mixed Magnetic Property of Co0.76Cu0.74[Fe(CN)6]·7.5H2O

2018 ◽  
Vol 71 (11) ◽  
pp. 914
Author(s):  
Yanfang Xia ◽  
Min Liu ◽  
Duxin Li
Keyword(s):  
Magnetic Field ◽  
Magnetic Moment ◽  
Effective Magnetic Moment ◽  
Lattice Parameter ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Co Precipitation ◽  
The Magnetic Field

Co0.76Cu0.74[Fe(CN)6]·7.5H2O was prepared as a powder by a chemical co-precipitation method. The powder X-ray diffraction patterns were indexed to the typical face-centred cubic structure with the lattice parameter a 10.55(2) Å. The temperature dependence of the χ−1 curve obeys the Curie–Weiss law (χ = C/(T – θ)) in the temperature range of 180–300 K. According to Curie–Weiss law, the calculated θ value is −54.82 K. In the paramagnetic state at 300 K, the effective magnetic moment (μeff = (8χT)1/2) is 3.58 μB per formula unit. The calculated theoretical effective magnetic moment is 4.06 μB. The magnetic field cooling measurements under a 200 Oe applied magnetic field show that the saturation magnetization value at 2 K of the complex Co0.76Cu0.74[Fe(CN)6]·7.5H2O is 1.528 emu g−1.

Decolorization of Methylene Blue by Photocatalyst in the Ag3PO4-AgI System

2014 ◽  
Vol 970 ◽  
pp. 29-32 ◽  
Author(s):  
Pongsaton Amornpitoksuk ◽  
Sumetha Suwanboon
Keyword(s):  
Methylene Blue ◽  
Mixed Phase ◽  
Photocatalytic Properties ◽  
Precipitation Method ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Co Precipitation

The co-effect of PO43- and I- on the formation of a heterosturucture photocatalyst in the Ag3PO4-AgI system was studied by the co-precipitation method between AgNO3 and the precipitating agent. The precipitating agent was prepared by varying the mole ratios between Na2HPO4 and KI. At 10 mol.% KI, the product showed the mixed phase between Ag3PO4 and un-identified phase. For 30 - 90 mol.% KI, the un-identified phase and AgI were detected in the x-ray diffraction patterns. The un-identified phase strongly adsorbed the methylene blue dye. The product prepared from 30 mol.% KI had the highest content of un-identified phase and also showed the highest degree of decolorization in the dark. The photocatalytic properties of products in this system were confirmed by the decolorization of methylene blue under visible illumination.

Carbonization Effect on Phase Structures of Zirconium Oxides with 2-3 Percent Yttrium

2014 ◽  
Vol 936 ◽  
pp. 181-186
Author(s):  
Zhi Qin Xue ◽  
Yong Quan Guo
Keyword(s):  
Tetragonal Phase ◽  
Structural Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zirconium Oxides ◽  
Percent Yttrium ◽  
Before And After ◽  
Cubic Structure ◽  
Diffraction Patterns ◽  
Rietveld Structural Refinement

Phase evolutions and structures of zirconium oxides with 2 percent yttrium before and after carbonization have been systemically studied with X-ray diffraction and Rietveld structural refinement. The carbonization decreases the structural stability of original ZrO2. According to the X-ray diffraction patterns, three phases with monoclinic, tetragonal and cubic structure coexist after carbonization. With increasing carbonizing temperature, the content of tetragonal phase in ZrO2with 2% mol Y2O3 doped increases，however, the phase content of monoclinic phase decreases. The content of tetragonal phase in ZrO2with 3% mol Y2O3doped increases greatly after carbonization. It implies that carbonization is beneficial for the formation of ZrO2tetragonal phase.

scholarly journals A novel UV pumped yellow-emitting phosphor Ba2YAlO5:Dy3+ for white light-emitting diodes

2019 ◽  
Vol 79 ◽  
pp. 03005
Author(s):  
Bin Deng ◽  
Jun Chen ◽  
Chong-song Zhou ◽  
Hui Liu
Keyword(s):  
Dopant Concentration ◽  
Uv Light ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
Solid State Route ◽  
Light Excitation ◽  
Diffraction Patterns ◽  
White Light Emitting Diodes ◽  
Uv Leds

A series of novel Dy3+ activated aluminate Ba2Y1-xDyxAlO5 (x = 0.01–0.30) red-emitting phosphors were synthesized through a high-temperature solid-state route at 1380°C. The X-ray diffraction patterns revealed that the samples were well crystallized in the space group P21/c (No. 14). The spectrum analysis revealed that under UV light excitation, Ba2YAlO5:Dy3+ phosphor exhibited blue and yellow peaks corresponding to 4F9/2–6H15/2 transition and 4F9/2–6H13/2 transition, respectively. The optimum dopant concentration of Dy3+ ions is around 2 mol% and the critical transfer distance of Dy3+ is calculated as 29 Å. The concentration quenching mechanism between Dy3+ has been investigated. Results indicate that Ba2YAlO5:Dy3+ offers the excellent optical properties as a potential yellow-emitting phosphor candidate for n-UV LEDs.

A new disordered langbeinite-type compound, K2Tb1.5Ta0.5P3O12, and Eu3+-doped multicolour light-emitting properties

2019 ◽  
Vol 75 (2) ◽  
pp. 213-220 ◽  
Author(s):  
Ya-Li Xue ◽  
Dan Zhao ◽  
Shi-Rui Zhang ◽  
Ya-Nan Li ◽  
Yan-Ping Fan
Keyword(s):  
Three Dimensional ◽  
Spectroscopic Properties ◽  
Energy Transfer Mechanism ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
First Time ◽  
Uv Excitation ◽  
The Eu

For the first time, a new langbeinite-type phosphate, namely potassium terbium tantalum tris(phosphate), K2Tb1.5Ta0.5(PO4)3, has been prepared successfully using a high-temperature flux method and has been structurally characterized by single-crystal X-ray diffraction. The results show that its structure can be described as a three-dimensional open framework of [Tb1.5Ta0.5(PO4)3]∞ interconnected by K+ ions. The TbIII and TaV cations in the structure are disordered and occupy the same crystallographic sites. The IR spectrum, the UV–Vis spectrum, the morphology and the Eu3+-activated photoluminescence spectroscopic properties were studied. A series of Eu3+-doped phosphors, i.e. K2Tb1.5–x Ta0.5(PO4)3:xEu3+ (x = 0.01, 0.03, 0.05, 0.07, 0.10), were prepared via a solid-state reaction and the photoluminescence properties were studied. The results show that under near-UV excitation, the luminescence colour can be tuned from green through yellow to red by simply adjusting the Eu3+ concentration from 0 to 0.1, because of the efficient Tb3+→Eu3+ energy-transfer mechanism.

Photoluminescence Properties of Eu2+,Mn 2+Co-Doped Ca10Si6O21Cl2 by Sol–Gel Method

2011 ◽  
Vol 239-242 ◽  
pp. 2124-2127 ◽  
Author(s):  
Yong Sheng Shi ◽  
Hui Rong Zhao ◽  
Bang Qing Wang ◽  
Su Hang Gu
Keyword(s):  
Emission Spectrum ◽  
White Light ◽  
Sol Gel ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
Reductive Atmosphere ◽  
Co Doped ◽  
The Ideal

White light-emitting materials of Eu2+, Mn2+-codoped Ca2SiO3Cl2were prepared. Luminescence properties and other samples phase were tested by X-ray diffraction (XRD) and fluorescence spectrophotometer (PL). The results showed that the temperature range of 730°C to 760°Cand the ideal holding time is 4h~5h, the emission spectrum of Eu2+-doped sample under excitation at 365nm wavelength was 426nm, 524nm in a weak reductive atmosphere of active carbon, the emission spectrum of Eu2+, Mn2+co-doped samples was 426nm, 524nm, 585nm, the three combined can produce white light.

Influence of Temperature on the Order-Disorder Transition in Gd2Zr2O7

2016 ◽  
Vol 697 ◽  
pp. 386-389 ◽  
Author(s):  
Jing Lin Shi ◽  
Zhi Xue Qu ◽  
Qun Wang
Keyword(s):  
Fluorite Structure ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Inconsistent Result ◽  
Disorder Transition ◽  
X Ray ◽  
Influence Of Temperature On ◽  
Diffraction Patterns ◽  
Co Precipitation ◽  
Increasing Temperature

Chemical co-precipitation method was used to prepare Gd2Zr2O7 powders. The powders were then heated in air at 1500°C, 1510°C, 1525°C, 1530°C, 1550°C, 1575°C, 1600°C for 5 h, and 1575°C, 1600°C for 10 h, respectively. The samples after heat treatment were characterized by X-ray diffraction and Raman spectroscopy. X-ray diffraction patterns reveal that order-disorder transition of Gd2Zr2O7 occurs between 1550°C and 1575°C. Prior to the transition, the relative intensity of peaks corresponding to the super-lattice of pyrochlores increases with the increasing temperature. On the other hand, Raman spectra give an inconsistent result from the X-ray diffraction data. No appreciable difference can be observed for all the samples though with peaks broadening as temperature increases. The spectra of the samples indicated as fluorite structure in X-ray diffraction patterns appear with six resolvable peaks which is quite different from the spectrum of ideal fluorite structure.

scholarly journals First Nanoparticles of a Conductor Based on the Organic Donor Molecule BETS: κ-(BETS)2FeCl4

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4444
Author(s):  
Kane Jacob ◽  
Christophe Faulmann ◽  
Dominique de Caro ◽  
Lydie Valade
Keyword(s):  
Energy Gap ◽  
Molar Ratio ◽  
Saturation Current ◽  
X Ray Diffraction ◽  
Donor Molecule ◽  
X Ray ◽  
Nano Crystalline ◽  
Current Voltage ◽  
Diffraction Patterns ◽  
Shockley Diode Model

Nanoparticles of the molecular superconductor (BETS)2FeCl4 were obtained by the electrochemical oxidation of BETS in the presence of [(C2H5)4N]FeCl4 and an amphiphilic imine (OATM), acting as a growth controlling agent. When the reaction was carried out with a molar ratio OATM/BETS of 10, roughly spherical nanoparticles exhibiting sizes in the 10–40 nm range were observed. X-ray diffraction patterns evidenced the growth of (BETS)2FeCl4 nanoparticles with the κ-type structure. The current-voltage characteristic recorded on an individual nanoparticle aggregate was fitted with a Shockley diode model. A saturation current of 1216 pA and a threshold voltage of 0.62 V were extracted from this model. This latter value was consistent with roughly half of the energy gap of the semiconducting nano-crystalline aggregate.

scholarly journals Inclusion compound of Fosinopril withβ-cyclodextrin

2009 ◽  
Vol 23 (1) ◽  
pp. 51-58 ◽  
Author(s):  
I. Bratu ◽  
Irina Kacso ◽  
Gh. Borodi ◽  
Daniela E. Constantinescu ◽  
Felicia Dragan
Keyword(s):  
Inclusion Compound ◽  
Diffraction Method ◽  
Differential Scanning Calorimetric ◽  
X Ray Diffraction ◽  
Preparation Methods ◽  
X Ray ◽  
Freeze Dried ◽  
Cyclodextrin Cavity ◽  
Diffraction Patterns ◽  
Co Precipitation

Solid state interactions of bioactive substance (4-cyclohexyl-1-[2-[(2-methyl-1-propanoyloxy-propoxy)-(4-phenylbutyl)phosphoryl]acetyl]-pyrrolidine-2-carboxylic acid, called Fosinopril), withβ-cyclodextrin (β-CD), the so-called inclusion compounds of a bioactive (cardiovascular) drug is obtained by different preparation methods: kneading, co-precipitation and freeze-drying. The so obtained compounds were investigated by FTIR spectroscopy, X-ray diffraction method, and differential scanning calorimetric measurements (DSC) to evidence their formation. X-ray diffraction patterns show that the inclusion compound was obtained for kneaded, co-precipitation and freeze-dried products. The crystalline/amorphous degree for these compounds was also investigated. Molecular modeling (MM+ molecular mechanics) shows the spatial architecture of the inclusion compound in good agreement with FTIR experimental data: the drug is included with the propanoyloxy-propoxy group insideβ-cyclodextrin cavity. These findings may constitute a direct contribution to the molecular encapsulation of Fosinopril intoβ-cyclodextrin, improving Fosinopril stability and bioavailability of the drug, also.

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