scholarly journals The effects of doping on the structural, optical and electric properties of Zn4Sb3 material

2016 ◽  
Vol 81 (3) ◽  
pp. 323-332 ◽  
Author(s):  
Mirela Vaida ◽  
Narcis Duteanu ◽  
Ioan Grozescu
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Visible Range ◽  
X Ray Diffraction ◽  
X Ray ◽  
Absorbance Spectra ◽  
Semiconducting Behavior ◽  
Scanning Electron

This paper presents results of the investigations regarding the obtaining and the characterization of the thermoelectric material Zn4Sb3 and (Zn1-xMx)4Sb3 where M = Ag and / or Sn. Obtaining of the materials was realized by melting high purity precursors into an oven where were kept isothermally for 12 hours at 1173 K. X-ray diffraction and scanning electron microscopy were used for structural and morphologic characterization. Optical band gap for each sample was determined from absorbance spectra recorded in the visible range 240-400 nm at room temperature. Electrical resistivity as function of temperature was measured and the electrical band gap was estimated for each of the obtained samples. The semiconducting behavior of the materials was reflected by these.

scholarly journals Preparation and Characterization of High Purity Anhydrous β-Lactose from α-Lactose Monohydrate at Mild Temperature

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ana L. López-Pablos ◽  
César C. Leyva-Porras ◽  
Macrina B. Silva-Cázares ◽  
Francisco E. Longoria-Rodríguez ◽  
Sergio A. Pérez-García ◽  
...  
Keyword(s):  
Room Temperature ◽  
Alcoholic Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lactose Monohydrate ◽  
Diffraction Patterns ◽  
Mild Temperature ◽  
Dietary Food ◽  
Scanning Electron

Lactose is a disaccharide of importance in humans dietary, food products, and the pharmaceutical industry. From the existing isomeric forms, β-lactose is rarely found in nature. Thus, in this work, a simple methodology to obtain anhydrous β-lactose (βL) from α-lactose monohydrate (αL·H2O) is presented. The αL·H2O powder was dispersed into a basic alcoholic solution (72 hours), at controlled conditions of temperature (27, 29, 31, and 32°C), without stirring. The slurry was dried at room temperature and characterized. Fourier transform infrared spectroscopy showed the formation of βL for the samples prepared at 29 and 32°C. Raman spectroscopy confirmed this result and suggested the occurrence of crystalline βL. Rietveld refinement of the X-ray diffraction patterns was employed to identify and quantify the composition of the isomers. The samples prepared at 29 and 31°C showed the formation of pure βL, while those at 27 and 32°C showed the presence of αL·H2O and a mixture of the two isomers, respectively. The morphology of the powders was studied by scanning electron microscopy, observing the formation of irregular shape αL·H2O particles and axe-like βL particles. Clearly, with this methodology, it was possible to obtain pure, crystalline, and anhydrous βL at mild temperature.

scholarly journals Preparation and characterization of self-reinforced paper using NaOH/thiourea aqueous solution at room temperature

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8191-8201
Author(s):  
Fuqiang Hu ◽  
Yucheng Hu ◽  
Lingling Zhang ◽  
Meixue Gan ◽  
Shangjun Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Room Temperature ◽  
Paper Strength ◽  
X Ray Diffraction ◽  
Fixed Temperature ◽  
Crystallinity Degree ◽  
X Ray ◽  
Scanning Electron

The aim of this paper was to enhance paper strength in NaOH/thiourea aqueous solution at room temperature. Paper from cotton pulp was saturated with room temperature NaOH/thiourea aqueous solution and placed at a fixed temperature (8, 15, and 20 °C) for a period of time (1 h, 2 h, 4 h, and 6 h). The morphology, X-ray diffraction (XRD), mechanical properties, and density of paper were characterized. The results indicated the paper was self-reinforced. Scanning electron microscopy (SEM) photographs indicated that the structure of the treated papers was increasingly compact with decreasing temperature. The XRD results showed that the crystallinity degree of the paper decreased from 80.0% to 60.0%. The stress at break of the treated papers increased by more than fivefold. The wet tensile strength of the treated papers increased remarkably.

Synthesis and Characterization of New Functional Material (C6H5CNH2nNH3)2PbI4(where n=0,1,2)

2011 ◽  
Vol 311-313 ◽  
pp. 2099-2105 ◽  
Author(s):  
Li Ling Guo ◽  
Xing Li ◽  
Han Xing Liu
Keyword(s):  
Electron Microscopy ◽  
Band Gap ◽  
Synthesis And Characterization ◽  
Molecular Formula ◽  
Reactant Ratio ◽  
Functional Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The new functional material, the hybrids with molecular formula (C6H5CNH2nNH3)2PbI4(where N=0,1,2) were synthesized by reactions in solution. The influences of the reactant ratio and the reaction time on the structures of the products were investigated. The structures and the properties of the hybrids were characterized using X-ray diffraction(XRD), scanning electron microscopy (SEM) and ultraviolet&visible (UV) adsorption spectra . The effect of number of methylene, n, on the structure forming and the band gap magnitude has been studied. The results demenstrate that the number of methylene has effect both on the forming of the layered structure and on the magnitude of the band gap.

Characterization of Crystalline Cu2SnS3 Synthesized via Low Temperature Solvothermal Method

2018 ◽  
Vol 780 ◽  
pp. 62-66 ◽  
Author(s):  
Mohamed S. Abdel Latif ◽  
N.M. Shaalan ◽  
Ahmed A. El-Moneim
Keyword(s):  
Band Gap ◽  
Solvothermal Method ◽  
Average Crystallite Size ◽  
Annealing Process ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Cu2SnS3flower-like nanoparticles consisted of nanoflakes were successfully produced using solvothermal technique at 120°C for 12 h. The precursors used in this process were CuCl2.2H2O, SnCl2.2H2O, and thiourea with dimethyl sulfoxide (DMSO) as a solvent. The results showed that the as-obtained product was triclinic Cu2SnS3with secondary phases CuS and SnS, and after annealing process, a pure triclinic was obtained. The crystal structure of the obtained samples was investigated by X-ray diffraction which assured the obtained data and the average crystallite size of as-prepared and annealed CTS was found to be 18.42 and 31.6 nm, respectively. Scanning electron microscopy (SEM) showed that the surface morphology has the shape of flower like consisted of nanoflakes. The transmission electron microscope (TEM) displayed the formation of sheets. The band gap was measured using UV-Vis absorption spectroscopy and found that the as-prepared sample has 1.97 eV band gap, which obtained for various phases CuS and SnS. However, this band was changed to 1.26 eV upon the heat treatment at 500°C for 10 minutes. This value of Egis comparable with the value reported by other literatures.

Structural and Optical Characterization of CdSe Films Grown by Chemical Bath Deposition

2011 ◽  
Vol 691 ◽  
pp. 119-126 ◽  
Author(s):  
J.R. Aguilar-Hernández ◽  
A. Espinosa-Bustamante ◽  
M.A. Hernández-Pérez ◽  
G.S. Contreras-Puente ◽  
M. Cárdenas-García ◽  
...  
Keyword(s):  
Band Gap ◽  
Cadmium Selenide ◽  
Chemical Bath Deposition ◽  
Room Temperature ◽  
Bulk Material ◽  
Optical Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Radiative Emission

We present in this work experimental results and their analysis concerning the structural and optical characterization of cadmium selenide (CdSe) films grown by the Chemical Bath Deposition (CBD) technique, at different bath temperaturesTd: 0≤Td≤80 °C. Structural characterization was carried out by using X-ray diffraction, whereas optical characterization was done by using optical absorption and photoluminescence spectroscopies. X-ray results showed a change of the crystalline structure as a function ofTd, from the zincblende to wurzite one whenTdincreases from 0 to 80 °C. The respective band-gap,Eg,was calculated from the absorption spectrum giving rise to values in the range 1.85 to 2.30 eV, as a function also ofTd. Thses values are higher than the well accepted value of 1.75 eV for the CdSe bulk material. The radiative emission was analyzed throughout the photoluminescence (PL) spectra. All samples showed radiative emission above the band-gap, at room temperature, this radiative emission having a dependence on the pressure inside the cryostat. A quenching of the PL signal is observed when the pressure is decreased at values as low as 60 mTorr.

Preparation and Characterization of CuO-Doped ZnO

2010 ◽  
Vol 152-153 ◽  
pp. 847-851
Author(s):  
Yan Li ◽  
Yun Ling Zou ◽  
Jian Gang Li
Keyword(s):  
Fourier Transformation ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Lattice Space ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Doped Zno ◽  
Scanning Electron

ZnO is an important functional semiconductor in application of photoelectric devices. ZnO nano-tubes and the CuO-doped ZnO have been successfully fabricated via hydrothermal method and a solution routine. The samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transformation infrared spectroscopy and room temperature photoluminescence measurement. The results show that the lattice space (d-value) of the CuO-doped ZnO increases while introducing CuO into its structure. Due to the interaction between Cu2+ and the surface atoms of ZnO, a photoluminescence confinement were observed in the CuO-doped ZnO compared with that of nano ZnO.

Microstructural Evolution and Corrosion Behavior of Carburized α-Fe Plates by Glucose

2013 ◽  
Vol 203-204 ◽  
pp. 94-98
Author(s):  
Eleftheria Maria Pechlivani ◽  
Fani Stergioudi ◽  
Christos Vogiatzis ◽  
Stefanos Skolianos ◽  
Danuta Stróż
Keyword(s):  
Room Temperature ◽  
Experimental Characterization ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
X Ray ◽  
Electrochemical Tests ◽  
Corrosion Rates ◽  
Current Densities ◽  
Scanning Electron

The aim of this paper is to obtain an experimental characterization of glucose-carburized substrates of α-Fe. The carburization process was achieved under vacuum condition using glucose as a carburizing medium. The process was carried out at several temperatures keeping the duration constant at 2h. The samples were treated at 400°C, 650°C and 900°C. The microstructure of the as produced coatings was observed by Scanning Electron Microscopy (SEM) and the formed phases were analyzed by X-Ray Diffraction (XRD). To investigate the corrosion properties of the carburized iron specimens, electrochemical tests were conducted. The samples were exposed to a solution of 3.5% wt. NaCl electrolyte, under quiescent conditions at room temperature and open to the air. The corroded samples were observed with use of Optical Microscopy in order to evaluate the corrosion effect on their surfaces. Carburization of iron samples at temperatures up to 650°C resulted in a shift of the polarization curves to lower current densities. Smaller corrosion rates were measured indicating higher corrosion resistance for these specimens.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

scholarly journals Synthesis and Characterization of Lithium-Ion Conductive LATP-LaPO4 Composites Using La2O3 Nano-Powder

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3502
Author(s):  
Fangzhou Song ◽  
Masayoshi Uematsu ◽  
Takeshi Yabutsuka ◽  
Takeshi Yao ◽  
Shigeomi Takai
Keyword(s):  
Room Temperature ◽  
Conduction Mechanism ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Nano Powder ◽  
Powder Addition

LATP-based composite electrolytes were prepared by sintering the mixtures of LATP precursor and La2O3 nano-powder. Powder X-ray diffraction and scanning electron microscopy suggest that La2O3 can react with LATP during sintering to form fine LaPO4 particles that are dispersed in the LATP matrix. The room temperature conductivity initially increases with La2O3 nano-powder addition showing the maximum of 0.69 mS∙cm−1 at 6 wt.%, above which, conductivity decreases with the introduction of La2O3. The activation energy of conductivity is not largely varied with the La2O3 content, suggesting that the conduction mechanism is essentially preserved despite LaPO4 dispersion. In comparison with the previously reported LATP-LLTO system, although some unidentified impurity slightly reduces the conductivity maximum, the fine dispersion of LaPO4 particles can be achieved in the LATP–La2O3 system.

scholarly journals MOVPE Growth of Quaternary (Al,Ga,In)N for UV Optoelectronics

2000 ◽  
Vol 5 (S1) ◽  
pp. 412-424
Author(s):  
Jung Han ◽  
Jeffrey J. Figiel ◽  
Gary A. Petersen ◽  
Samuel M. Myers ◽  
Mary H. Crawford ◽  
...  
Keyword(s):  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Optoelectronic Devices ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Peak Energy ◽  
Movpe Growth ◽  
Pl Emission

We report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.

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