scholarly journals Electrochemical and structural properties of Ni(II)-alumina composites as an annealing temperature function

2019 ◽  
Vol 51 (3) ◽  
pp. 339-351
Author(s):  
Zorica Mojovic ◽  
Tatjana Novakovic ◽  
Milos Mojovic ◽  
Tanja Barudzija ◽  
Miodrag Mitric
Keyword(s):  
Structural Properties ◽  
Annealing Temperature ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Xrd Analysis ◽  
High Specific Surface Area ◽  
Tetrahedral Position ◽  
Temperature Function ◽  
Naoh Solution ◽  
Alumina Composites

Alumina powders, pure and doped with nickel, were synthetized by sol-gel method and calcined at 500, 900 and 1100?C in order to obtain mesoporous structures with a high specific surface area, well adapTab. to catalytic application. The characterization of samples was performed by XRD, EPR spectroscopy and electrochemical impedance spectroscopy (EIS). XRD analysis showed that the addition of Ni2+, as well as the annealing temperature, affects the structural properties of the obtained composites. EPR analysis revealed the traces of Fe3+ impurities, the presence of oxy defects in alumina and Ni2+ in tetrahedral position for samples calcined at 1100?C. The impedance of the Nafion/alumina modified GCE depended on combined effect of porous structure and surface properties of alumina samples. The electrochemical behavior of a glassy carbon electrode modified with Ni (II)-doped aluminas was studied in 0.5 M NaOH solution, with and without methanol. The electrochemical activity of nickel-doped alumina composites was dictated by the amount of present NiO impurity.

LiMn1.5Ni0.25Fe0.2M0.05O4 Nanoparticles as a Cathode Material for Rechargeable Li-Ion Batteries

2020 ◽  
Vol 835 ◽  
pp. 149-154
Author(s):  
Haitham A. Abdellatif ◽  
Mostafa M.M. Sanad ◽  
Elsayed M. Elnaggar ◽  
Mohamed M. Rashad ◽  
Gamal M. El-Kady
Keyword(s):  
Annealing Temperature ◽  
Sol Gel ◽  
Combustion Method ◽  
Xrd Analysis ◽  
Charge Transfer Resistance ◽  
Li Ion Batteries ◽  
Transfer Resistance ◽  
Auto Combustion ◽  
Li Ion ◽  
Kinetic Diffusion

New series of spinel LiNi0.25Fe0.2Mˊ0.05Mn1.5O4 (Mˊ = Cu, Mg or Zn) cathode materials have been purposefully tailored using sol-gel auto-combustion method at low annealing temperature ~ 700°C for 3 h. The XRD analysis showed that all substituted (LNFMO-Mˊ) samples are comported with the main structure of undoped (LNFMO) with crystalline disordered spinel Fd-3m structure. TEM images revealed the octahedron-shape like morphology for the particles and the LNFMO-Zn sample has the widest particle size distribution. EIS spectra evidenced that a typical one semicircle (LNFMO-Mg) was revealed for each cell, suggesting the absence of ionic conductivity contribution. The values of charge transfer resistance (Rct) were equal to 9.3, 6.7, 6.0 and 4.4 kΩ for LNFMO, LNFMO-Cu, LNFMO-Mg indicating that the Zn-doped sample has the fastest kinetic diffusion rate and lowest activation energy of conduction.

Effect of Cobalt Content on the Structural Properties of Zirconia Prepared by Sol-Gel Method

2020 ◽  
Vol 1000 ◽  
pp. 227-232
Author(s):  
Nurhayati Indah Ciptasari ◽  
Adri Nora ◽  
Lutviasari Nuraini ◽  
Lusiana ◽  
Nono Darsono ◽  
...  
Keyword(s):  
Structural Properties ◽  
Sol Gel ◽  
Cobalt Content ◽  
Secondary Phase ◽  
Xrd Analysis ◽  
Weight Percent ◽  
Sem Images ◽  
Monoclinic Crystal ◽  
Gel Method ◽  
Sol Gel Method

Zirconia (ZrO2) powders doped with cobalt were prepared by sol-gel method using inorganic salt of zirconium (IV) chloride (ZrCl4) as precursor. The amount of cobalt was varied in the range of 4–16% weight percent to study the effect to structural properties. X-ray diffraction (XRD) analysis suggested the resulting phases were zirconium oxide (Baddeleyite) with monoclinic crystal system along with cobalt oxide as secondary phase. The increasing cobalt content caused the XRD peaks to shift into lower angle due to substitution of Zr atom to smaller Co atom in crystal lattice. Scanning electron microscope (SEM) images showed the samples with higher Co content had smoother surface. Generally, the microstructures of Co doped zirconia powders consisted of large agglomerates with small particles on the surface.

scholarly journals Morphological and Structural Properties of Sol-Gel Derived ZnO Thin Films Spin-Coated on Different Substrates

2020 ◽  
Vol 301 ◽  
pp. 35-42
Author(s):  
Nabihah Kasim ◽  
Zainuriah Hassan ◽  
Way Foong Lim ◽  
Sabah M. Mohammad ◽  
Hock Jin Quah
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
High Resolution ◽  
Structural Properties ◽  
Low Cost ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Precursor Solution ◽  
Xrd Analysis ◽  
Zno Thin Films

In this work, ZnO thin films were prepared by the low-cost sol-gel deposition method onto six different substrates (glass, ITO coated glass, sapphire (Al2O3), p-Si, p-GaN and polyethylene terephthalate (PET)) to study the effects of these substrates on the morphological and structural properties of the produced films. Precursor solution is Zinc acetate dihydrate based dissolved in ethanol with monoethanolamine (C2H7NO) added to act as a stabilizing agent to the sol. The corresponding ZnO thin films were characterized using field emission scanning electron microscopy (FESEM), high resolution X-ray diffraction (XRD) and atomic force microscopy (AFM). Results revealed distinct morphological and structural properties of ZnO thin films deposited on each substrate. The most uniform morphology was identified on glass, owing to the acquisition of the averagely stable grain sizes (58 nm – 61 nm) and thin film thicknesses (280 nm – 325 nm). High resolution XRD analysis showed that the films deposited on glass, ITO, p-Si, and p-GaN were attributed to hexagonal crystallite structures while the films deposited on sapphire and PET substrates exhibited amorphous phases. Amongst the samples, the ZnO thin film spin coated on p-Si demonstrated preferred orientation in (002) direction.

THERMALLY-DRIVEN STRUCTURAL CHANGES OF SPUTTERED COPPER ALUMINUM OXIDE FILMS (Cu–Al2O3) GROWN BY LAYER STACKING METHOD

2017 ◽  
Vol 24 (Supp01) ◽  
pp. 1850002
Author(s):  
WEI QIANG LIM ◽  
SHANMUGAN SUBRAMANI ◽  
MUTHARASU DEVARAJAN
Keyword(s):  
Crystallite Size ◽  
Structural Properties ◽  
Structural Changes ◽  
Annealing Temperature ◽  
Compressive Strain ◽  
Rf Magnetron Sputtering ◽  
Xrd Analysis ◽  
X Ray ◽  
Layer Stacking ◽  
Deposited Films

Copper aluminium oxide (Cu–Al2O3) films were synthesized on Si(111) substrates through RF magnetron sputtering by using the layer stacking technique. Cu and Al2O3 targets were used to deposit Cu and Al2O3 thin films under Ar atmosphere, respectively and the deposited films were then annealed under N2 environment at 350[Formula: see text]C, 450[Formula: see text]C and 550[Formula: see text]C for 6[Formula: see text]h. The structural properties of the films were investigated by using X-ray diffraction (XRD) while the surface morphology and topography of the deposited films were examined through Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX) and Atomic Force Microscopy (AFM). XRD analysis revealed the existence of multiple phases of CuO, Al2O3 and CuAl2O4 in the deposited films on Si(111) substrates. As a result of the annealing effect, the peak intensities of CuO, Al2O3 and CuAl2O4 were found to be increased along with the shifting of peak positions. Williamson–Hall (WH) analysis was also implemented to analyze the structural properties such as crystallite size, stress, strain, and energy density. Based on the three models used in WH analysis, the changes in the crystallite size and strain of the films were indicated to be anomalous with the changes in the annealing temperature. Moreover, the strain of films was also showed to be changed from compressive strain into tensile strain. The FESEM results also indicated the formation of various surface morphologies under various annealing temperatures whereas EDX analysis showed an increased atomic percentage of Cu, Al, and O due to the effect of increase in annealing temperature. The AFM analysis showed that the surface roughness of the deposited films increased with the increase in the annealing temperature.

Synthesis and Characterization of Sol–Gel Prepared Silver Nanoparticles

2014 ◽  
Vol 13 (01) ◽  
pp. 1450004 ◽  
Author(s):  
Dharamvir Singh Ahlawat ◽  
Rekha Kumari ◽  
Rachna ◽  
Indu Yadav
Keyword(s):  
Silver Nanoparticles ◽  
Absorption Spectra ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Silica Matrix ◽  
Silver Clusters ◽  
Different Temperatures ◽  
Uv Visible ◽  
Average Size

Silver nanoparticles (SNPs) have been successfully prepared using sol–gel method by annealing the sample at 550°C for 30 min. The SNPs were not confirmed by X-ray diffraction (XRD) analysis when the annealing temperature was considered at 450°C. They were also not confirmed without calcination of the sample. The physical mechanism of silver clusters formation in the densified silica matrix with respect to thermal treatment has been understood. The presence of silver metal in the silica matrix was confirmed by XRD analysis and TEM image of the samples. The average size of nanoparticles dispersed in silica matrix was determined as 10.2 nm by the XRD technique. The synthesized nanocomposites were also characterized by UV-Visible spectroscopy with a peak in the absorption spectra at around 375 nm. The distribution of particle size has been reported here in the range from 8 nm to 25 nm by TEM observations of the sample prepared at 550°C. The spherically smaller size (≈10 nm) SNPs have reported the surface plasmons resonance (SPR) peak less than or near to 400 nm due to blue-shifting and effect of local refractive index. Without annealing the silica samples the absorption spectra does not show any peak around 375 nm. The FTIR spectroscopy of the three types of samples prepared at different temperatures (room temperature, 450°C and 550°C) has also been reported. This spectra have provided the identification of different chemical groups in the prepared samples. It has been predicted that the size of SNPs by XRD, UV-Visible and TEM results have agreed well with each other. It may be concluded that formation of SNPs is a function of annealing temperature.

Thermal Annealing-Activated Crystallinity Metastasis of Al:ZnO Thin Films

2015 ◽  
Vol 1109 ◽  
pp. 181-185 ◽  
Author(s):  
Mohd Firdaus Malek ◽  
Mohamad Hafiz Mamat ◽  
M.Z. Musa ◽  
M. Rusop
Keyword(s):  
Thin Films ◽  
Thermal Annealing ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dip Coating Technique ◽  
Multilayered Thin Films

Multilayered thin films of aluminum-doped ZnO (Al:ZnO) have been deposited by the sol-gel dip coating technique. Experimental results indicated that the thermal annealing temperature affected the crystallinity of the Al:ZnO films. X-ray diffraction (XRD) analysis showed that thin films were preferentially orientated along the c-axis plane. The preferred orientation along (0 0 2) plane becomes more pronounced as the thermal annealing being increased. The film thickness ranges between 180 and 690 nm. In our experiments, the most optimum condition of Al:ZnO annealing temperature was both 500 oC.

Influences of annealing temperature on the optical and structural properties of (Ba,Sr)TiO3 thin films derived from sol–gel technique

2002 ◽  
Vol 408 (1-2) ◽  
pp. 200-205 ◽  
Author(s):  
Hu-Yong Tian ◽  
Wei-Gen Luo ◽  
Ai-Li Ding ◽  
Jongwan Choi ◽  
Changho Lee ◽  
...  
Keyword(s):  
Thin Films ◽  
Structural Properties ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Gel Technique

Preparation and electrical properties of gadolinium-doped strontium tungstate electrolyte for SOFC

2020 ◽  
Vol 13 (03) ◽  
pp. 2050010
Author(s):  
Jihai Cheng ◽  
Ming Wang
Keyword(s):  
Electrical Properties ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Combustion Method ◽  
Xrd Analysis ◽  
Doping Amount ◽  
Sintered Ceramic ◽  
Auto Combustion ◽  
Electrical Conductivities ◽  
Text Content

Gadolinium-doped strontium tungstate (Sr[Formula: see text]GdxWO[Formula: see text]) powders were synthesized by the sol–gel auto-combustion method, and their electrical properties were investigated. The phase formation of Sr[Formula: see text]GdxWO[Formula: see text] powders was studied by the X-ray diffraction (XRD) analysis. The characterization of microstructure was carried out on the sintered ceramic discs. Electrochemical impedance spectroscopy (EIS) was used to estimate the electrical properties. The results displayed that these crystalline powders were scheelite-type tetragonal structures and demonstrated higher sinterability. The Sr[Formula: see text]GdxWO[Formula: see text] electrolyte ceramics with a relative density over 95% of the theoretical density were obtained after the sintering process. The electrical conductivities of Sr[Formula: see text]GdxWO[Formula: see text] increased significantly with increasing of doped-Gd[Formula: see text] content and reached [Formula: see text] S[Formula: see text]cm[Formula: see text] at 800∘C, when the doping amount was [Formula: see text]. At last, this study demonstrated that Sr[Formula: see text]GdxWO[Formula: see text] is an effective strategy to optimize middle or low-temperature SOFC.

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