scholarly journals Effect of Ni, N Co-Doped on Properties of AgSnO2 Contact Materials

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 707
Author(s):  
Jingqin Wang ◽  
Jianyu Yang ◽  
Yancai Zhu ◽  
Guangzhi Zhang ◽  
Delin Hu ◽  
...  
Keyword(s):  
Density Functional ◽  
Electrical Contact ◽  
Sol Gel ◽  
Powder Metallurgy Method ◽  
Energy Bands ◽  
Contact Materials ◽  
Co Doping ◽  
Overlap Population ◽  
N Doping ◽  
Co Doped

The first-principles method based on density functional theory was used to analyze the impurity formation energies, energy bands, density of states, electron overlap population and elastic modulus of SnO2, SnO2–Ni, SnO2–N and SnO2–Ni–N. SnO2 powders with different additives were prepared by the sol-gel method, and then X-ray diffraction experiments and wettability experiments were carried out. The powder metallurgy method was used to prepare AgSnO2 contacts with different additives. The simulation experiments on hardness, electrical conductivity and electrical contact were carried out. The simulation results show that the conductivity of Ni–N co-doped SnO2 is best, and more impurity levels are introduced into the forbidden band, thereby increasing the carrier concentration, reducing the band gap, and improving the conductivity. The experimental results show that Ni, N doping does not change the structure of SnO2, so doped SnO2 still belongs to the tetragonal system. Ni–N co-doping can better improve the wettability between SnO2 and Ag, reduce the accumulation of SnO2 on the contact surface and reduce the contact resistance. Ni–N co-doped SnO2 has the smallest hardness, improving ductility, molding and service life of the AgSnO2 contact material.

scholarly journals Study on Simulation and Experiment of Y-Mo Co-Doped AgSnO2 Contact Materials

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 724
Author(s):  
Jingqin Wang ◽  
Yongqiang Chang ◽  
Yancai Zhu ◽  
Guangzhi Zhang ◽  
Guanglin Huang
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Density Functional ◽  
Sol Gel ◽  
Electrical Performance ◽  
Powder Metallurgy Method ◽  
Contact Materials ◽  
Co Doping ◽  
Calculation Results ◽  
Co Doped

Due to the shortcomings of AgSnO2 as a contact material, models of SnO2, Y-SnO2, Mo-SnO2, and Y-Mo-SnO2 were built to calculate their electrical and mechanical properties based on the first principles of density functional theory. The Y-Mo co-doped SnO2 was the most stable of all the models according to the enthalpy change and the impurity formation energy. By analyzing the energy band structure and the density of states, it was shown that the doped models are still direct bandgap semiconductor materials. The valence band moved up and the conduction band moved down after doping, reducing the band gap and enhancing conductivity. With the reduced energy for carrier transition, the electrical performance of Y-Mo co-doped SnO2 was improved best. The mechanical properties of SnO2 were completely improved by Y-Mo co-doping according to calculation results. The doped SnO2 materials were prepared by the sol-gel method, and the doped AgSnO2 materials were prepared by the powder metallurgy method. X-ray diffraction, hardness, conductivity and wettability experiments were undertaken, with experimental results showing that AgSnO2 can be improved comprehensively by Y-Mo co-doping, verifying the conclusions of the simulation. Overall, the present study provides an effective method for the preparation of high-performance contact materials.

Effect of Cu, S Co-Doping on Properties of AgSnO2 Contact Material

2020 ◽  
Vol 12 (8) ◽  
pp. 1242-1251
Author(s):  
Wang Jingqin ◽  
Liu Zhou ◽  
Chen Ling ◽  
Yu Shuangmiao ◽  
Zhu Yancai
Keyword(s):  
Density Functional ◽  
Electrical Contact ◽  
Sol Gel ◽  
Hole Mobility ◽  
First Principles Calculation ◽  
Powder Metallurgy Method ◽  
Co Doping ◽  
The Stability ◽  
Conductive Properties ◽  
Co Doped

The stability, elastic properties and conductive properties of Cu-doped SnO2, S-doped SnO2 and Cu, S-codoped SnO 2were studied by using the first-principles calculation method based on the density functional theory. The corresponding doped SnO2 powders were prepared by sol–gel method, while AgSnO2–Cu and AgSnO2–Cu–S contacts were obtained by powder metallurgy method for experimental verification. No diffraction peaks were associated with Cu and S in the XRD patterns of the doped SnO2 powders, indicating that the doped SnO2 retained the tetragonal crystal structure. The doping formation energy of Cu, S co-doped system was found to be lower than that of Cu single doping system and S single doping system. The bulk modulus, shear modulus and Young's modulus of the co-doped system became lower, the ability to resist compression deformation and shear deformation was also weakened, while its toughness was greatly improved. The hardness of the AgSnO2–Cu–S contact was 103.55 HV, which is less than the hardness of the AgSnO2–Cu contact (112.86 HV). The calculations indicated that Cu, S co-doping could narrow the band gap, reduce the hole effective mass and the acceptor ionization energy, improve the hole mobility, and enhance the conductivity of the material. The electrical contact simulation experiments showed that the conductive properties, arc corrosion resistance and welding resistance of AgSnO2–Cu–S contact were better than those of the AgSnO2–Cu contact. The conductivity of AgSnO2–Cu–S contact was 29.948 mS · m–1, the contact resistance was 1.109 Ωm ; the average arc duration and average arc energy were 1.480 ms and 171.65 mJ, respectively.

Synergistic Effect of Eu3+ and Sm3+ Co-Doping on Photocatalytic Activity of TiO2 Nanoparticles

2011 ◽  
Vol 197-198 ◽  
pp. 891-894 ◽  
Author(s):  
Cheng Zhi Jiang ◽  
Xu Dong Lu
Keyword(s):  
Photocatalytic Activity ◽  
Synergistic Effect ◽  
Sol Gel ◽  
Blue Shift ◽  
Nano Particles ◽  
Absorption Profile ◽  
Co Doping ◽  
The Matrix ◽  
Co Doped ◽  
The Eu

Pure TiO2, Eu3+and Sm3+co-doping TiO2composite nanoparticles have been prepared by sol-gel method and characterized by the techniques such as XRD, SEM and DRS. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate their photocatalytic activity. The matrix distortion of TiO2nano-particles increases after co-doping of Eu3+and Sm3+and a blue-shift of the absorption profile are clearly observed. The results show that co-doping of Eu3+and Sm3+inhibits the phase transformation of TiO2from anatase to rutile, decreases the diameter of TiO2nano-particles and significantly enhance the photocatalytic activity of TiO2. The Eu3+and Sm3+co-doped into TiO2nano-particles exert a synergistic effect on their photocatalytic activity.

The Synthesis and Optical Properties of Zinc-Nitrogen Co-Doped TiO2 Thin Films Using Sol–Gel Derived Spin-Coating Method

2021 ◽  
Vol 16 (6) ◽  
pp. 967-973
Author(s):  
Shuai Zhao ◽  
Dong-Xue Lin ◽  
Yu-Xin Wang
Keyword(s):  
Optical Properties ◽  
Spin Coating ◽  
Sol Gel ◽  
Crystal Plane ◽  
Utilization Rate ◽  
Doping Content ◽  
Spin Coating Method ◽  
Co Doping ◽  
Coating Method ◽  
N Doping

All of the TiO2 films including intrinsic TiO2 film, Zn single doped film with 2.0 at% content and N doped films with 4.0 at%, 6.0 at%, 8.0 at% and 10.0 at% content, were obtained by butyl titanate (Ti(OC4H9)4) as a titanium source, zinc nitrate (Zn(NO3)2·6H2O) as zinc source and urea (H2 NCONH2) as nitrogen source, which was calcined at 600 °C on the glass substrate and Si substrate using sol–gel spin coating method. The structures, morphology and optical properties of various films were analyzed and studied by X ray diffract meter (XRD), ultraviolet-visible spectrophotometer (UV-Vis) and scanning electron microscope (SEM). The results indicated that the main crystal plane of TiO2 film was (101) and any impurity crystal plane didn't appear. All samples had obvious red shifts in the absorbing edge overall and reduced significantly the width of forbidden band, especially, the N doping content with 8.0 at% was surprised to investigate the strongest (101) peak intensity, the sharpest peak type, the best meritocratic orientation, the greatest red shift of the absorption spectrum, the lowest optical band gap value of 3.356 eV, and the highest utilization rate of visible light of the sample. However, the surface morphology of the others films except the N doping content with 8.0 at% is not further improved by co-doping, that is, their surfaces were still rough, had obvious voids and uneven distribution between the grains. Meanwhile, the intensity of the (101) crystalline diffraction peaks of these samples were reduced and the crystalline spacing generally increased after co-doping.

Effect of cobalt doping on microstructures and dielectric properties of ZnO

2019 ◽  
Vol 97 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Ye Zhao ◽  
Fan Tong ◽  
Mao Hua Wang
Keyword(s):  
Zno Nanoparticles ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Sem Analysis ◽  
Co Doping ◽  
In Doping ◽  
Zno Powders ◽  
Doped Zno ◽  
Zno Crystal ◽  
Co Doped

Pure and cobalt-doped ZnO nanoparticles (2.5, 5, 7.5, and 10 atom % Co) are synthesized by sol–gel method. The as-synthesized nanoparticles are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM) analysis. The nanoparticles of 0, 2.5, and 5 atom % Co-doped ZnO exhibited hexagonal wurtzite structure and have no other phases. Moreover, the (101) diffraction peaks position of Co-doped ZnO shift toward a smaller value of diffraction angle compared with pure ZnO powders. The results confirm that Co ions were well incorporated into ZnO crystal lattice. Simultaneously, Co doping also inhibited the growth of particles, and the crystallite size decreased from 43.11 nm to 36.63 nm with the increase in doping concentration from 0 to 10 atom %. The values of the optical band gap of all Co-doped ZnO nanoparticles gradually decreased from 3.09 eV to 2.66 eV with increasing Co content. Particular, the dielectric constant of all Co-doped ZnO ceramics gradually increased from 1.62 × 103 to 20.52 × 103, and the dielectric loss decreased from 2.36 to 1.28 when Co content increased from 0 to 10 atom %.

scholarly journals Microstructure refinement and physical properties of Ag-SnO2 based contact materials prepared by high-energy ball milling

2013 ◽  
Vol 45 (2) ◽  
pp. 173-180 ◽  
Author(s):  
V. Cosovic ◽  
M. Pavlovic ◽  
A. Cosovic ◽  
P. Vulic ◽  
M. Premovic ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Physical Properties ◽  
Ball Milling ◽  
Electrical Contact ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Powder Metallurgy Method ◽  
Contact Materials ◽  
Energy Ball ◽  
Electrical Contact Materials

High energy ball milling was used in order to improve dispersion of metal oxide in Ag-SnO2 electrical contact materials. The processed Ag-SnO2 (92:8) and Ag-SnO2In2O3 (87.8:9.30:2.9) powder mixtures were subsequently consolidated to bulk solid pieces by conventional powder metallurgy method. The characterization of the prepared samples included microstructural analysis by XRD and SEM, as well as measurements of physical properties such as density, hardness and electrical conductivity. The results of X-Ray analysis point to reduction of crystallite size after milling of about ten times. Microstructures of sintered Ag-SnO2 and Ag-SnO2 In2O3 materials display very fine dispersion of the oxide components in silver matrix. Somewhat higher uniformity was obtained for Ag-SnO2 In2O3 material which was illustrated by results of SEM analysis and more consistent microhardness values. The obtained values of studied physical properties were found to be in accordance with observed higher dispersion of metal oxide particles and comparable to properties of commercial electrical contact materials of this type.

Bandgap control and optical properties of β-Si3N4 by single- and co-doping from a first-principles simulation

2018 ◽  
Vol 32 (14) ◽  
pp. 1850178 ◽  
Author(s):  
Xuefeng Lu ◽  
Xu Gao ◽  
Junqiang Ren ◽  
Cuixia Li ◽  
Xin Guo ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Formation Energy ◽  
Blue Shift ◽  
Functional Theory ◽  
Co Doping ◽  
Charge Density Difference ◽  
Co Doped

Bandgap tailoring of [Formula: see text]-Si3N4 is performed by single and co-doping by using density functional theory (DFT) of PBE functional and plane-wave pseudopotential method. The results reveal that a direct bandgap transfers into an indirect one when single-doped with As element. Also, a considerate decrease of bandgap to 0.221 eV and 0.315 eV is present for Al–P and As–P co-doped systems, respectively, exhibiting a representative semiconductor property that is characteristic for a narrower bandgap. Compared with other doped systems, Al-doped system with formation energy of 2.67 eV is present for a more stable structure. From charge density difference (CDD) maps, it is found that the blue area between co-doped atoms increases, illustrating an enhancement of covalent property for Al–P and Al–As bonds. Moreover, a slightly obvious “Blue shift” phenomenon can be obtained in Al, Al–P and Al–As doped systems, indicating an enhanced capacity of responses to light, which contributes to the insight for broader applications with regard to photoelectric devices.

Magnetic and electrical transport properties of Sr2Ti1−xCoxO4 ceramics by sol–gel

2017 ◽  
Vol 31 (17) ◽  
pp. 1750195
Author(s):  
Li Zhang ◽  
Yibao Li ◽  
Zhen Tang ◽  
Yan Deng ◽  
Hui Yuan ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Low Temperatures ◽  
Sol Gel ◽  
Variable Range Hopping ◽  
Electrical Transport Properties ◽  
Co Doping ◽  
Hopping Model ◽  
Variable Range Hopping Model ◽  
Co Doped

Microstructures, electrical transport and magnetic properties of Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics are investigated. With Co doping, the Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics remain tetragonal structure while the grain size is decreased with doping. Magnetic moment is enhanced with Co doping and ferromagnetism is observed at low temperatures for Co-doped Sr[Formula: see text]TiO[Formula: see text]. The Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] and Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] show semiconductor-like transport properties, which can be well fitted by Mott variable range hopping model. The results will provide an effective route to synthesize Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics as well as to investigate the physical properties.

Structural and Electrical Properties of (Cu, Co) Co-Doped ZnO Thin Film

2013 ◽  
Vol 774-776 ◽  
pp. 964-967
Author(s):  
Ping Cao ◽  
Yue Bai
Keyword(s):  
Electrical Properties ◽  
Sol Gel ◽  
Hall Effect Measurement ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Co Doping ◽  
Structural And Electrical Properties ◽  
Doped Zno ◽  
Cu Ions ◽  
Co Doped

Successful synthesis of Cu, Co co-doped ZnO film is obtained by sol-gel method. The structural and electrical properties of the sample were investigated. X-ray diffraction spectroscopy analyses indicate that the Co and Cu co-doping can not disturb the structure of ZnO. No additional peaks are observed in the Zn0.99Co0.01CuxO and Cu+ and Co2+ substitute for Zn2+ without changing the wurtzite structure. By Hall-effect measurement p-type conductivity was observed for the Cu co-doped film. XPS result confirmed Cu ions are univalent in the films.

Effect of Co-Doping on Electronic and Magnetic Properties in Ti2NiAl Heusler Alloy

2012 ◽  
Vol 602-604 ◽  
pp. 575-578
Author(s):  
Bo Wu ◽  
Xiu De Yang ◽  
Song Zhang
Keyword(s):  
Heusler Alloy ◽  
Density Functional ◽  
Magnetic Moments ◽  
High Energy ◽  
Type Structure ◽  
Local Spin Density Approximation ◽  
Lattice Constants ◽  
Co Doping ◽  
The Density Functional Theory ◽  
Co Doped

By using local spin density approximation (LSDA) scheme within the density functional theory (DFT), the structure, magnetism and electronic properties of Co-doped Heusler alloy Ti2NiAl with Hg2CuTi- and Cu2MnAl-type structure are comprehensively investigated. The results revealed that whole of the doped alloys with Hg2CuTi-type structure are ground configurations and half-metallic. With the increase of Co-doped concentration, the lattice constants and total magnetic moments in per unit are changed linearly, and the discrepancies of total energy between Hg2CuTi- and Cu2MnAl structure are also enhanced. Analysis on density of states (DOS) revealed that the Fermi level should gradually move to high-energy orientation with increasing Co content due to stronger hybridization of d-electronic atoms.

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