scholarly journals Synthesis, Growth, and Electrical Transport Properties of Pure and -Doped Triglycine Sulphate Crystal

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Farhana Khanum ◽  
Jiban Podder
Keyword(s):  
Electrical Transport ◽  
Conductivity Measurement ◽  
Electrical Transport Properties ◽  
Electrical Conductivity Measurement ◽  
Triglycine Sulphate ◽  
Direct Current Conductivity ◽  
Vis Spectroscopy ◽  
Vicker’S Microhardness ◽  
Dielectric Loss Increase

Pure triglycine sulphate (TGS) and LiSO4-doped TGS crystals were grown from aqueous solution by natural evaporation method. The grown crystals were characterized by UV-vis spectroscopy, electrical conductivity () measurement, dielectric studies, microhardness, and thermogravimetry/differential thermal analysis. Pure TGS and LiSO4-doped TGS crystals were found highly transparent and full faced. The direct current conductivity is found to increase with temperature as well as dopant concentrations. Curie temperature remains the same for pure and doped crystals, but dielectric constant and dielectric loss increase with dopant concentration. The Vicker’s microhardness of the LiSO4-doped TGS crystals along (001) face is found higher than that of pure TGS crystals. Etching studies illustrate the quality of the doped crystal. The experimental results evidence the suitability of the grown crystal for optoelectronic applications.

scholarly journals Low Surface Roughness Graphene Oxide Film Reduced with Aluminum Film Deposited by Magnetron Sputtering

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1428
Author(s):  
Xiaowei Fan ◽  
Xuguo Huai ◽  
Jie Wang ◽  
Li-Chao Jing ◽  
Tao Wang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Electron Transfer ◽  
Graphene Oxide ◽  
Magnetron Sputtering ◽  
Chemical Reduction ◽  
Graphene Film ◽  
Conductivity Measurement ◽  
Electrical Conductivity Measurement ◽  
Vis Spectroscopy ◽  
Hcl Solution

Graphene film has wide applications in optoelectronic and photovoltaic devices. A novel and facile method was reported for the reduction of graphene oxide (GO) film by electron transfer and nascent hydrogen produced between aluminum (Al) film deposited by magnetron sputtering and hydrochloric acid (HCl) solution for only 5 min, significantly shorter than by other chemical reduction methods. The thickness of Al film was controlled utilizing a metal detection sensor. The effect of the thickness of Al film and the concentration of HCl solution during the reduction was explored. The optimal thickness of Al film was obtained by UV-Vis spectroscopy and electrical conductivity measurement of reduced GO film. Atomic force microscope images could show the continuous film clearly, which resulted from the overlap of GO flakes, the film had a relatively flat surface morphology, and the surface roughness reduced from 7.68 to 3.13 nm after the Al reduction. The film sheet resistance can be obviously reduced, and it reached 9.38 kΩ/sq with a high transmittance of 80% (at 550 nm). The mechanism of the GO film reduction by electron transfer and nascent hydrogen during the procedure was also proposed and analyzed.

Modifying Jahn-Teller distortion by epitaxial stress in LaMnO3 films for tunning electron localization

2021 ◽  
Author(s):  
Xin Chen ◽  
Baohua Wang ◽  
Tongxin Ge ◽  
Haoming Wei ◽  
Bingqiang Cao
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Reciprocal Space ◽  
Electron Localization ◽  
Electrical Transport Properties ◽  
High Quality ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Distortion

Abstract The effect of epitaxial stress on Jahn-Teller distortion in epitaxial LaMnO3 (LMO) films has been investigated. Both 2θ-ω scans and reciprocal space maps indicate that LMO samples are subjected to compressive stress. Obvious Laue oscillations can be detected in 2θ-ω scans, indicating the high quality of samples. Reciprocal space maps of symmetry peak (001) and asymmetry peak (-103) imply different epitaxial stress for LMO films deposited on different substrates. Raman spectra measurements reveal that the degree of Jahn-Teller distortion can be well tuned via the epitaxial stress which may further influence on the electron localization in the films. This study might benefit to understanding the correlation between crystalline structure and electrical transport properties of LMO films and related LMO-based superlattices.

Preparation and characterization of La1.8Sr0.2CuO4/La1.9Sr0.1CuO4 superconducting bilayers

2013 ◽  
Vol 28 (S1) ◽  
pp. S7-S11
Author(s):  
Y. Zhang ◽  
Y.H. An ◽  
Y. Xing ◽  
D.Y. Dong ◽  
S.L. Wang ◽  
...  
Keyword(s):  
Electrical Transport ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Electrical Transport Properties ◽  
Bilayer Films ◽  
Deposition Parameters ◽  
Surface Morphologies

The c-oriented La1.8Sr0.2CuO4 and La1.9Sr0.1CuO4 bilayer films were deposited on (001) SrTiO3 single-crystal substrates by using the pulsed laser deposition technique. The effects of deposition parameters on the quality of thin films were investigated. The crystal structures and surface morphologies were characterized by means of XRD and SEM, and the results showed that an as-prepared film deposited with the optimized parameters has high quality. Then La1.8Sr0.2CuO4/La1.9Sr0.1CuO4 bilayers structure was prepared using the optimized parameters for each corresponding layer, and the electrical transport properties were measured. Interesting rectifying properties were observed at both room and low temperatures, and the rectifying ratio at low temperature was found to be much higher than that at room temperature.

Investigation of Buffer Layers for GaN Grown by MBE

2000 ◽  
Vol 639 ◽  
Author(s):  
Feng Yun ◽  
Michael A. Reshchikov ◽  
Paolo Visconti ◽  
Keith M. Jones ◽  
Dongfeng Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Electrical Transport ◽  
Topological Analysis ◽  
Buffer Layers ◽  
Structural Quality ◽  
Electrical Transport Properties ◽  
Medium Temperature ◽  
Aln Buffer

ABSTRACTThe structural quality of the buffer layer juxtaposed to the substrate is pivotal in attaining high quality GaN layers. In MBE deposition, low temperature, medium temperature and high temperature AlN buffer layers are at the disposal of the grower. There are quite a few reports, some discussing the benefits of high temperature buffer layers and others doing the same for low temperature buffer layers. The reports emanate from different laboratories; and due to stringent parameter control required, it is difficult to compare one type of buffer with another. To gain some insight, we undertook an investigation wherein these varieties of buffer layers were grown on nitridated sapphire substrate under similar conditions for a comparative analysis. In addition to the single buffer layers of both GaN and AlN varieties, some combinations of stacked buffer layers, including cases where these buffer layers were separated by GaN layers, were employed. Structural analysis by high resolution X-ray diffractometry and topological analysis by AFM were carried out to assess the quality of the epilayers grown on these buffers. Hall measurements at room temperature were carried out to characterize the electrical transport properties.

Effect of the growth temperature and nitrogen precursor on the structural and electrical transport properties of SmN thin films

MRS Advances ◽  
2017 ◽  
Vol 2 (3) ◽  
pp. 165-171
Author(s):  
Jay R. Chan ◽  
Mohamed Al Khalfioui ◽  
Stéphane Vézian ◽  
Joe Trodahl ◽  
Benjamin Damilano ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Temperature ◽  
Electrical Transport ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
Doped Semiconductors ◽  
Structural And Electrical Properties ◽  
Growth Character

ABSTRACTWe report on the structural and electrical properties of epitaxial SmN thin films grown by molecular beam epitaxy. The effect of the growth temperature and nitrogen precursor, either pure molecular N2 or NH3 was investigated. The structural quality of SmN was assessed by X-ray diffraction and the epitaxial growth character is observed over the entire range of growth temperatures, from 300°C to 800°C, with both nitrogen precursors. The highest quality films are produced at a growth temperature of about 430°C by using N2 as a nitrogen precursor. Hall Effect and resistivity measurements establish that SmN films are heavily n-type doped semiconductors, suggesting the presence of nitrogen vacancies, a recurring phenomenon in rare earth nitride compounds.

Nanostructural Characteristics and Electrical Conductivity of Copper Nanoparticles-Polypropylene Nanocomposites for Bipolar Plate Application

2013 ◽  
Vol 634-638 ◽  
pp. 2214-2217
Author(s):  
Sari Katili ◽  
Akhmad Herman Yuwono
Keyword(s):  
Electrical Conductivity ◽  
Copper Nanoparticles ◽  
Production Cost ◽  
Conductivity Measurement ◽  
Bipolar Plate ◽  
Electrical Conductivity Measurement ◽  
Wet Chemistry ◽  
Polypropylene Nanocomposites ◽  
Vis Spectroscopy ◽  
Polypropylene Matrix

The current research is aimed at obtaining suitable nanocomposites for bipolar plate application in fuel cell, which fulfill the requirement for electrical and mechanical properties and low production cost. For this purpose, copper nanoparticles (Cu-NPs) were embedded in polypropylene matrix through wet-chemistry technique with the presence of polypropylene-grafted maleic anhydride as the coupling agent. The resulting nanocomposites were characterized with UV-Vis spectroscopy, TEM, SEM, TGA and electrical conductivity measurement. It was found that the addition of Cu-NPs up to 1.50 wt% has improved effect on the electrical conductivity up to 14.43 S/cm. However, further increase of Cu-NPs loading to 2.00 wt% adversely reduced the electrical conductivity down to 9.31 S/cm, as a consequence of severe agglomeration and large pores formation.

Highly soluble tetrasubstituted lanthanide bis-phthalocyanines; synthesis, characterization, electrical properties and aggregation studies

2016 ◽  
Vol 20 (08n11) ◽  
pp. 1065-1074 ◽  
Author(s):  
Ahmet T. Bilgiçli ◽  
Armağan Günsel ◽  
Mehmet Kandaz ◽  
Ahmet Altındal ◽  
Hüseyin Cömert
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Electrical Properties ◽  
Electrical Transport ◽  
Hole Mobility ◽  
Electrical Transport Properties ◽  
Force Microscopy ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Coating Method

We report the synthesis, characterization and electrical properties of lanthanide metal based bis-phthalocyanines, {M[Pc-(β-HHT)4]2} (HHT:1-hydroxyhexane-3-ylthio){ M [Formula: see text] Lu[Formula: see text] (2), Eu[Formula: see text] (3), and Yb[Formula: see text] (4)}. The interaction of bis-phthalocyanines with Ag[Formula: see text] and Pd[Formula: see text] metal ions were investigated by UV-vis spectroscopy and atomic force microscopy. Thin films of bis-phthalocyanine molecules were prepared by spin-coating method. The surface morphology of thin films were performed with Atomic Force Microscopy as further investigate. The electrical transport properties of ITO/Pc/Al devices were investigated. At low voltages all the films showed an ohmic conduction, whereas at higher voltage levels the conduction is dominated by space charged limited conduction with exponential distribution of trapping levels. Measurements of current density as a function of inverse temperature at constant applied voltage yielded a hole mobility values, μp[Formula: see text], [Formula: see text] and [Formula: see text] m2.sn[Formula: see text].V[Formula: see text] for lanthanium phthalocyanines. From the analysis of frequency, ω, dependence of electrical conductivity, σac. it was found that the [Formula: see text] obeys the power law given by σac = Aωs, in which the frequency exponent “s” decreases with temperature.

scholarly journals Exploratory Monitoring of the Quality and Authenticity of Commercial Honey in Ecuador

Foods ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 105 ◽  
Author(s):  
Lorena Salvador ◽  
Michelle Guijarro ◽  
Daniela Rubio ◽  
Bolívar Aucatoma ◽  
Tanya Guillén ◽  
...  
Keyword(s):  
Honey Bees ◽  
Reducing Sugars ◽  
Conductivity Measurement ◽  
Principal Component ◽  
Economic Importance ◽  
Critical Problem ◽  
Spectroscopic Analyses ◽  
Chemical Threats ◽  
Raman And Ir Spectroscopy

Honey is one of the oldest sweetening foods and has economic importance, making this product attractive to adulteration with cheap sugars. This can cause a critical problem in the honey industry and a possible health risk. The present work has the aim of evaluating the authenticity of honey commercialized in two different provinces of Ecuador (Pichincha and Loja) by performing physicochemical and spectroscopic analyses. For this study 25 samples were collected from different places and markets and characterized by water, sucrose, reducing sugars and electric conductivity measurement. Also, their Raman and Infrared (IR) spectra were recorded and analysed using a Principal Component Analysis (PCA) in order to verify the quality of the honeys. In addition, a screening of several pesticides was performed in order to verify possible chemical threats to human health and honey bees. It was found that 8 samples have a deviation from the Standard established parameters. Two of them have a high difference in the content of sucrose and reducing sugars, which are located deviated from all the other samples in the PCA of the applied vibrational spectroscopy (IR/Raman), shaping two clear clusters. The results show that Raman and IR spectroscopy is appropriate techniques for the quality control of honey and correlates well with the physicochemical analyses.

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