Hydrothermal Synthesis and Luminescence Property of Nanoscaled BiPO4:Eu3+ Powders

2016 ◽  
Vol 16 (4) ◽  
pp. 3827-3830 ◽  
Author(s):  
Xiaolei Shi ◽  
Yun Liu ◽  
Jin Zhang ◽  
Kun Zhang ◽  
Peng Li ◽  
...  

Aseries of Bi1−xPO4:xEu3+ phosphors were prepared using a simple hydrothermal method. The effects of pH and Eu3+ doping on the structure, morphology and luminescence properties of BiPO4:Eu3+ were investigated systematically. X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM) results reveal that the as-prepared BiPO4 crystals are in a low temperature monoclinic phase (LTMP), and have a rod-like structure with a size in the range of 1–5 μm at pH 1. Increasing the pH to 2 transforms the BiPO4 to its hexagonal phase (HP), with peanut-like structures ranging from 50 to 150 nm. At pH 1, when the doping level is increased to 0.07, the phase transformation from LTMP to HP occurs, meaning that the amount of HP components increase with increasing Eu3+ doping. Furthermore, all the diffraction peaks of the Bi1−xPO4:xEu3+ can be fitted very well to HP when x = 0.11. The photoluminescence (PL) spectra suggest that orangered luminescence can be observed in the series of BiPO4:Eu3+ phosphors, and that concentration quenching occurs when x = 0.07.

2010 ◽  
Vol 428-429 ◽  
pp. 126-131
Author(s):  
Wei Zhong Lu ◽  
Chun Wei ◽  
Qui Shan Gao

Polymethylene bis(p-hydroxybenzoates) were prepared from methyl p-hydroxybenzoate and different diols by melted transesterification reaction. Three liquid crystalline polyesters were synthesized from terephthaloyl dichloride and polymethylene bis(p-hydroxybenzoates). Its structure, morphology and properties were characterized by Ubbelohde viscometer, Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), polarized optical microscopy (POM) with a hot stage, and wide-angle X-ray diffraction (WAXD). Results indicated that the intrinsic viscosities were between 0.088 and 0.210 dL/g. Optical microscopy showed that the TLCP has a highly threaded liquid crystalline texture and a high birefringent schlieren texture character of nematic phase and has wider mesophase temperature ranges for all polyesters. DSC analysis were found that the melting point (Tm), isotropic temperature (Ti) of TLCPs decreased and the temperature range of the liquid crystalline phase became wider with increased number of methylene spacers in the polyester. The WAXD results showed that TLCPs owned two strong diffraction peaks at 2θ near 19° and 23°.


2007 ◽  
Vol 43 (2) ◽  
pp. 141-150 ◽  
Author(s):  
G.P. Vassilev ◽  
K.I. Lilova ◽  
J.C. Gachon

Phase equilibria were studied in the system Ni-Sn-Bi. Special attention has been paid to the identification of the recently found ternary phase. For this purpose samples were synthesized using intimately mixed powders. After annealing and quenching, all alloys were analyzed by scanning electron microscope and by X-ray diffraction. The results give evidences about the existence of a ternary compound with approximate formula Ni6Sn2Bi to Ni7Sn2Bi. Overlapping of some neighboring diffraction peaks of this phase with NiBi and Ni3Sn_LT is the reason for the difficulties related to the X-ray diffraction identification of the ternary phase.


2019 ◽  
Vol 811 ◽  
pp. 34-39
Author(s):  
Rachmawati Rachmawati ◽  
Ida Ayu Dwitasari

Vanillin is an additive widely used in foods and beverages. This research focused on formation of inclusion complexes to improve the stability of vanillin. The amylose in starch can act as a host molecule by forming a single helix known as V-amylose which has a hydrophobic channel. In this research, the starch was suspended in water (2.8% (w/v)) and was sonicated for 30 minutes. The mixture was subsequently heated at 180 °C to dissolve starch. Vanillin dissolved in ethanol was then mixed with the starch solution at around 85 °C. The concentration of vanillin was varied at 10%, 30% and 50% (w/w, based on the weight of starch). The resulting inclusion complexes were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), and Scanning Electron Microscope (SEM). FTIR characterizations were conducted on starch, vanillin, physical mixture of starch-vanillin, and the inclusion complexes. The results showed there were differences on some vibration peaks between the physical mixture of starch-vanillin and the inclusion complex. The XRD results depicted different patterns of the diffraction peaks for the inclusion complexes compared to native starch and vanillin which showed that the starch-vanillin complexes were successfully formed.


2013 ◽  
Vol 631-632 ◽  
pp. 78-81 ◽  
Author(s):  
Xiao Jing Yang ◽  
Lan Lan Li ◽  
Xin Hua Zhang ◽  
Pan Shi ◽  
Yue Tian ◽  
...  

We reported on a convenient route to synthesize rhombohedra boron nitride (r-BN) micro-rod using urea (CO(NH2)2) and sodium borohydride (NaBH4) through thermal treatment at 1300 °C. The structure, morphology, and chemical composition of the obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). In order to determine the phase composition and abundance of the as-synthsized simples, Rietveld refinement has been performed to analyze the XRD data using the Rietan-2000 program. The results show that the abundance of r-BN is about 90.6 wt % and h-BN is 9.4 wt % deduced from Reitveld refinement.


2002 ◽  
Vol 753 ◽  
Author(s):  
I. Baker ◽  
R. G. Quiller ◽  
M. Robson ◽  
D. Wu

ABSTRACTPowders of near-equiatomic Fe and Co were mechanically milled with additions of Zr, C, Ni, Cu and/or B for 60 hr using stainless steel balls in a Svegari attritor operated at 1300 r.p.m. under argon. The milled powders were examined before and after annealing at 600 °C. The morphologies and sizes of the powders were examined using a scanning electron microscope. The grain sizes were characterized from the widths of X-ray diffraction peaks obtained using a computer-controlled x-ray diffractometer and the lattice parameters were determined. The resulting magnetic properties were measured using a vibrating sample magnetometer.


2019 ◽  
Vol 4 (2) ◽  
pp. 668-673
Author(s):  
Rikson Siburian ◽  
Saur L Raja ◽  
Minto Supeno ◽  
Crystina Simanjuntak

Coconut shell is one of the potential biomass as carbon sources. Coconut shell is converted to charcoal through the carbonization process. The potential of charcoal from coconut shells can be synthesized into graphene. Graphene is a derivative of one of the carbon allotropes, namely graphite, where carbon is in the form of thin plates with sp2 orbitals arranged hexagonally. The process of making graphene which is coconut shell dried in the sun then pyrolysis into charcoal then mixed with activated carbon as a reducing agent at 600 ° C for 1 hour to produce graphene. The graphene produced is characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX). The results by XRD analysis showed the resulting peaks were not sharp and slightly widened at the diffraction peaks at 24 ° and 44 °. The results of SEM-EDX analysis at 4000x magnification show the surface size and shape of the structure that is smaller, thinner and reduced buildup on the graphene structure. graphene that has been successfully synthesized was tested on a coin battery. The coin battery cathode which was replaced with graphene succeeded in turning on the light.  


Clay Minerals ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 515-524 ◽  
Author(s):  
H. Taubald ◽  
A. Bauer ◽  
T. Schäfer ◽  
H. Geckeis ◽  
M. Satir ◽  
...  

AbstractThe alteration and transformation behaviour of the Tertiary Hammerschmiede Smectite and the Jurassic Opalinus Shale in an alkaline solution was studied in column experiments. The Hammerschmiede Smectite is proposed as potential backfill material and the Opalinus Shale as host rock for the Swiss low-level nuclear waste storage site. Over a period of 18 months, the evolution of permeability, pH and solution concentrations were measured. After the experiment, the columns were cut into pieces to study the mineralogical and the chemical evolution of the clays. X-ray diffraction (XRD) revealed no significant appearance or disappearance of diffraction peaks at the end of the experiments. The scanning electron micrographs of the clays revealed that both clays exhibited a precipitation zone, which extends from 0 to 2 cm below the infiltration surface. Both clays showed significant differences in the evolution of pH and hydraulic conductivity. The solution front crossed the Opalinus Shale column entirely after only 11 weeks and the initial values for K+ and Na+ were conserved in the solution. For both clays, the salt concentrations in the percolating fluids mirror the evolution of pH.


2014 ◽  
Vol 989-994 ◽  
pp. 383-386
Author(s):  
Li Min Dong ◽  
Fei Lv ◽  
Qin Li ◽  
Zhi Dong Han ◽  
Xian You Zhang

A series of Eu3+, Dy3+ actived Ca1-xBaxSnO3 phosphors were synthesized by coprecipitation method. The structure, morphology and fluorescence property of phosphors were investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectroscopy. SEM results showed that the as-prepared phosphors are smooth and uniform with the cubic morphology. The incorporation of a small amount of Ba to CaBaSnO3 improved the emission characteristics. Fluorescence spectrum showed the emission intensity is the best with the incorporation of Ba2+ (x = 0.3), when calcination temperature is 900°C.


1990 ◽  
Vol 210 ◽  
Author(s):  
Daniel BÉLanger ◽  
Guylaine Laperriere ◽  
Michel Preda

AbstractScanning electron microscopy and X-ray diffraction have been used to characterize the transformation of electrodeposited molybdenum trisulfide thin film and powder to molybdenum trioxide. Scanning electron microscopy shows that the formation of molybdenum trioxide is accompanied by an enhancement of the surface area of the film as the relatively smooth molybdenum trisulfide is converted to molybdenum trioxide displaying a platelet structure. X-Ray diffraction revealed that amorphous molybdenum sulfide is converted to polycrystalline molybdenum oxide upon heating in air above 400°C. The observed diffraction peaks obtained when molybdenum sulfide was heated at 400°C for 15 min. correspond fairly well with those of orthorhombic molybdenum trioxide. However, when the molybdenum sulfide powder was heated at 400°C for a period of only about 2 min., additional diffraction peaks were observed. The latter can be attributed to monoclinic molybdenum dioxide.


2012 ◽  
Vol 472-475 ◽  
pp. 2452-2457 ◽  
Author(s):  
Xiao Hui Jiang ◽  
Jun Feng Ma ◽  
Jie Cheng ◽  
Jing Rui Fang ◽  
Yong Sun

Cadmium molybdate (CdMoO4) nanoparticles, cube-like crystallites and octahedral microparticles have been successfully synthesized by a molten salt method at 270°C. The structure, morphology and luminescent property of the resultant powders were characterized by X-ray diffraction (XRD), transmission electron microcopy (TEM), scanning electron microcopy (SEM), and photoluminescence (PL), respectively. The resultant samples are a pure phase of CdMoO4 and without any impurities. PL spectra results show that the optical properties of CdMoO4 particles are strongly relied on their morphologies.


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