scholarly journals Effects of Pr and Yb Dual Doping on the Thermoelectric Properties of CaMnO3

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1807 ◽  
Author(s):  
Cuiqin Li ◽  
Qianlin Chen ◽  
Yunan Yan
Keyword(s):  
Electron Microscopy ◽  
Figure Of Merit ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Thermoelectric Figure ◽  
X Ray ◽  
Transmission Electron ◽  
New Strategy ◽  
Low Toxicity

There has been research on CaMnO3 with natural abundance, low toxicity, and low cost as promising candidates for n-type thermoelectric (TE) materials. In this paper, Ca1−2xPrxYbxMnO3 with different Pr and Yb contents (x = 0, 0.01, 0.02, 0.03, 0.04 and 0.05) were synthesized by means of coprecipitation. With X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM), researchers characterized the phase structure and morphology of all the samples. The oxidation states of manganese were determined by X-ray photoemission spectroscopy (XPS). The role of Ca-site dual doping in the TE properties was also investigated. Increasing the Pr and Yb contents leads to decreases in the electrical resistivity and Seebeck coefficient, leading to a power factor of 3.48 × 10−4 W·m−1·K−2 for x = 0.04 at 773 K, which is its maximum. Furthermore, the thermal conductivity (κ) decreases with increasing x, and κ = 1.26 W m−1·K−1 is obtained for x = 0.04 at 973 K. Ca0.92Pr0.04Yb0.04MnO3 exhibit a ZT (thermoelectric figure of merit) value of 0.24 at 973 K, approximately 3 times more than that of the pristine CaMnO3. Thus, the reported method is a new strategy to enhance the TE performance of CaMnO3.

scholarly journals A Novel X-Ray Radiation Sensor Based on Networked SnO2 Nanowires

2019 ◽  
Vol 9 (22) ◽  
pp. 4878 ◽  
Author(s):  
Jae-Hun Kim ◽  
Ali Mirzaei ◽  
Hyoun Woo Kim ◽  
Hong Joo Kim ◽  
Phan Quoc Vuong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Low Cost ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Radiation Sensor ◽  
Sno2 Nanowires ◽  
Radiation Sensors

X-Ray radiation sensors that work at room temperature are in demand. In this study, a novel, low-cost real-time X-ray radiation sensor based on SnO2 nanowires (NWs) was designed and tested. Networked SnO2 NWs were produced via the vapor–liquid–solid technique. X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM) analyses were used to explore the crystallinity and morphology of synthesized SnO2 NWs. The fabricated sensor was exposed to X-rays (80 kV, 0.0–2.00 mA) and the leakage current variations were recorded at room temperature. The SnO2 NWs sensor showed a high and relatively linear response with respect to the X-ray intensity. The X-ray sensing results show the potential of networked SnO2 NWs as novel X-ray sensors.

Novel synthesis of AlN nanowires with controlled diameters

2001 ◽  
Vol 16 (11) ◽  
pp. 3133-3138 ◽  
Author(s):  
Jun Liu ◽  
X. Zhang ◽  
Yingjiu Zhang ◽  
Rongrui He ◽  
Jing Zhu
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
High Efficiency ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Synthesis Mechanism ◽  
X Ray ◽  
Novel Synthesis ◽  
Transmission Electron ◽  
New Synthesis

A relatively low-cost, high-efficiency method is reported to synthesize AlN nanowires, using carbon nanotubes as templates. The AlN nanowires were fabricated at 1100 °C, for 60 min. The diameters of the product could be roughly controlled by the sizes of carbon nanotubes selected as starting materials. The AlN nanowires obtained were among the thinnest ever known. X-ray diffraction, selected-area diffraction, energy dispersive spectroscopy, and high-resolution transmission electron microscopy, etc. were employed to characterize the products, which were found to be single crystals with some defects. The axes of the nanowires are normal to {1010} crystal planes. A new synthesis mechanism is proposed.

Effects of Thermo-Mechanical Treatment on the Microstructure of AA7085 Aluminum Alloy

2014 ◽  
Vol 794-796 ◽  
pp. 1193-1198 ◽  
Author(s):  
Hong Wei Tong ◽  
Wen Yi Liu ◽  
Guang Jie Huang ◽  
Qing Liu
Keyword(s):  
Electron Microscopy ◽  
Rolled Plate ◽  
X Ray Diffraction ◽  
Warm Deformation ◽  
X Ray ◽  
Free Zone ◽  
Transmission Electron ◽  
Hardness Tests ◽  
Continuous Chain

The microstructure of pre-aged AA7085 rolled plate was studied by means of hardness tests, optical microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and electrical conductivity tests. The results show that supper refined and homogeneous precipitates were formed during pre-aging, but the hardness of the alloy was still relatively low. There occurred a large number of dislocations when the warm deformation was introduced, and the size of the intragranular precipitates firstly increases and then decreases and then increases with the dislocation density increasing, which was caused by the role of dislocations on inhibiting the formation of GP zone and promoting the nucleation and transformation ofηphase. Meanwhile, the distribution of grain boundary precipitates also changed from continuous chain to coarsening interrupted distribution and the precipitate free zone (PFZ) broadened obviously.

scholarly journals Biosynthesis of spinel nickel ferrite nanowhiskers and their biomedical applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hajar Q. Alijani ◽  
Siavash Iravani ◽  
Shahram Pourseyedi ◽  
Masoud Torkzadeh-Mahani ◽  
Mahmood Barani ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Nickel Ferrite ◽  
Biomedical Applications ◽  
Leishmania Major ◽  
X Ray Diffraction ◽  
Green Method ◽  
X Ray ◽  
Transmission Electron ◽  
Low Toxicity

AbstractGreener methods for the synthesis of various nanostructures with well-organized characteristics and biomedical applicability have demonstrated several advantages, including simplicity, low toxicity, cost-effectiveness, and eco-friendliness. Spinel nickel ferrite (NiFe2O4) nanowhiskers with rod-like structures were synthesized using a simple and green method; these nanostructures were evaluated by X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, and X-ray energy diffraction spectroscopy. Additionally, the prepared nanowhiskers could significantly reduce the survival of Leishmania major promastigotes, at a concentration of 500 μg/mL; the survival of promastigotes was reduced to ≃ 26%. According to the results obtained from MTT test (in vitro), it can be proposed that further studies should be conducted to evaluate anti-leishmaniasis activity of these types of nanowhiskers in animal models.

scholarly journals Facile Synthesis of Calcium Carbonate Nanoparticles from Cockle Shells

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Kh. Nurul Islam ◽  
A. B. Z. Zuki ◽  
M. E. Ali ◽  
Mohd Zobir Bin Hussein ◽  
M. M. Noordin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Carbonate ◽  
Large Scale ◽  
Low Cost ◽  
Analytical Techniques ◽  
Variable Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir

A simple and low-cost method for the synthesis of calcium carbonate nanoparticles from cockle shells was described. Polymorphically, the synthesized nanoparticles were aragonites which are biocompatible and thus frequently used in the repair of fractured bone and development of advanced drug delivery systems, tissue scaffolds and anticarcinogenic drugs. The rod-shaped and pure aragonite particles of30±5 nm in diameter were reproducibly synthesized when micron-sized cockle shells powders were mechanically stirred for 90 min at room temperature in presence of a nontoxic and nonhazardous biomineralization catalyst, dodecyl dimethyl betaine (BS-12). The findings were verified using a combination of analytical techniques such as variable pressure scanning electron microscopy (VPSEM), transmission electron microscopy (TEM), Fourier transmission infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), and energy dispersive X-ray analyser (EDX). The reproducibility and low cost of the method suggested that it could be used in industry for the large scale synthesis of aragonite nanoparticles from cockle shells, a low cost and easily available natural resource.

scholarly journals Growth and Characterization of Ni Nano-Micro Structures in the Presence of Ethylenediamine

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 397 ◽  
Author(s):  
Lingxiao Chen ◽  
Hang Liu ◽  
Linghao Liu ◽  
Yifan Zheng ◽  
Haodong Tang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Alkaline Conditions ◽  
Naoh Solution ◽  
Micro Structures ◽  
Scanning Electron

Ni nano-micro structures have been synthesized via a solution reduction route in the presence of ethylenediamine (EDA) under strong alkaline conditions. The phase composition, morphology, and microstructure of the resulting products are investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The presence of EDA plays an important role in the formation of Ni nano-micro structures, and microflowers or microspheres assembled from nanosized horns can be produced by changing the amount of EDA. The size of Ni nano-micro structures is dependent on the NaOH concentration, and long chains assembled from Ni nano-micro structured microspheres can be obtained by reducing the amount of NaOH solution used. The role of both EDA and NaOH in the reduction of Ni (II) to Ni, as well as in the growth of Ni nano-micro structures, has been discussed, and a possible formation mechanism of these Ni nano-micro structures has been proposed based on the experimental results.

Effects of indium-filling and synthesis pressure on the thermoelectric properties of CoSb3

2014 ◽  
Vol 28 (15) ◽  
pp. 1450118 ◽  
Author(s):  
Le Deng ◽  
Li Bin Wang ◽  
Jie Ming Qin ◽  
Tao Zheng ◽  
Xiao Peng Jia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Processing Time ◽  
Room Temperature ◽  
Thermoelectric Figure Of Merit ◽  
X Ray Diffraction ◽  
Thermoelectric Figure ◽  
X Ray ◽  
Scanning Electron

In x Co 4 Sb 12 skutterudite compounds have been prepared successfully at different synthesis pressures by high pressure and high temperature (HPHT) method, the processing time has been reduced from a few days to half an hour. In addition, the effect of synthesis pressure on the thermoelectric properties of In 0.4 Co 4 Sb 12 compounds has been investigated in this paper. The structure of In 0.4 Co 4 Sb 12 samples was evaluated by means of X-ray diffraction and scanning electron microscopy (SEM). The Seebeck coefficient, electrical resistivity and thermal conductivity were all measured in the temperature range of room temperature to 673 K. The sample synthesized at 2.0 GPa showed the highest power factor of 29.3 μWcm-1K-2 at 373 K. A dimensionless thermoelectric figure of merit (ZT) of 0.51 at 673 K was achieved for n-type In 0.4 Co 4 Sb 12 prepared at 1.3 GPa, which was significantly enhanced in comparison with pure CoSb 3.

Facile Preparation of Cu(OH)2@TiO2 Nanowire Arrays for Photoelectrochemical Water Splitting

2014 ◽  
Vol 881-883 ◽  
pp. 968-971
Author(s):  
Dan Yan ◽  
Wei Dong Shi ◽  
Wei Qiang Fan
Keyword(s):  
Electron Microscopy ◽  
Water Splitting ◽  
Tin Oxide ◽  
Diffuse Reflectance ◽  
Low Cost ◽  
Nanowire Arrays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Facile Preparation

Cu (OH)2@TiO2nanowire arrays (NWAs) on the Fluorine-doped tin oxide (FTO) substrates had been fabricated via an simple and facile deposition method. The as-prepared Cu (OH)2@TiO2NWAs were subsequently characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-Ray diffraction (XRD), UVVis diffuse reflectance spectra (DRS), X-ray photoelectron spectrometer (XPS) and photoelectrochemical measurements. This results suggested that the Cu (OH)2@TiO2NWAs efficiently impeded the recombination between photoelectrons and holes. Therefore, this approach would afford a simple, effective, facile and low-cost method for preparation photoanode, which would enhance the hydrogen generating capability of TiO2from water splitting.

scholarly journals Synthesis of an optical catalyst for cracking contaminating dyes in the wastewater of factories using indium oxide in nanometer and usage in agriculture

2019 ◽  
Vol 21 (4) ◽  
pp. 98-105 ◽  
Author(s):  
Ishaq F. E. Ahmed ◽  
Ahmed I. El-Shenawy ◽  
Moamen S. Refat
Keyword(s):  
Electron Microscopy ◽  
Indium Oxide ◽  
Organic Dyes ◽  
Low Cost ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
20 Nm

Abstract Herein, the photocatalytic degradation of the Congo Red (CR) and Crystal Violet (CV) dyes in an aqueous solution were discussed in the presence of an indium(III) oxide (In2O3) as optical catalyst efficiency. The caproate bidentate indium(III) precursor complex has been synthesized and well interpreted by elemental analysis, molar conductivity, Fourier transform infrared (FT-IR), UV-Vis, and thermogravimetric (TGA) with its differential thermogravimetric (DTG) studies. The microanalytical and spectroscopic assignments suggested that the associated of mononuclear complex with 1:3 molar ratio (M3+:ligand). Octahedral structure is speculated for this parent complex of the caproate anion, CH3(CH2)4COO− ligand. The In2O3 NPs with nanoscale range within 10–20 nm was synthesized by a simple, low cost and eco-friendly method using indium(III) caproate complex. Indium oxide nanoparticles were formed after calcination of precursor in static air at 600°C for 3 hrs. The structural, grain size, morphological and decolorization efficiency of the synthesized NPs were characterized using the FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and transmission electron microscopy (TEM) analyses. It was worthy mentioned that the prepared In2O3 NPs showed a good photodegradation properties against CR and CV organic dyes during 90 min.

scholarly journals Controllable Combustion Synthesis of SiC Nanowhiskers in a Si-C-N System: The Role of the Catalyst

2019 ◽  
Vol 10 (1) ◽  
pp. 252
Author(s):  
Min Xia ◽  
Hong-Yan Guo ◽  
Muhammad Irfan Hussain
Keyword(s):  
Electron Microscopy ◽  
First Principles ◽  
Morphological Characterization ◽  
First Principles Calculations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Absorption Energy ◽  
Transmission Electron ◽  
Nanometer Catalysts

Silicon carbide (SiC) nanowhiskers (NWs) constitute an important type of optical and structural materials. Herein, SiC NWs were successfully combustion synthesized (CSed) in a Si-C-N system using tungsten (W) as a catalyst. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction were used to characterize the SiC NWs. Results of morphological characterization indicated that the W-catalyzed CSed SiC NWs products were fluffy from surface to the core, and they were about several hundred micrometers in length with diameters less than 1 μm. For the comprehensive understanding of the initial growing progress of W-catalyzed CSed SiC NWs, the absorption behavior of C, N, and Si atoms on the crystal planes of W (100), W (110), and W (111) surfaces was investigated by using first-principles calculations. The calculated surface energy (Esurf) of the studied W surfaces and the absorption energy of C, N, and Si atoms on different sites, indicate that the C atom has a priority to sink to the nanometer catalysts grain of W, and the pre-sunk C atom then reacts with Si atom to form NWs.

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