scholarly journals Comparison of Urea and Citric Acid Complexing Agents and Annealing Temperature Effect on the Structural Properties of - and -Alumina Nanoparticles Synthesized by Sol-Gel Method

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
A. Rajaeiyan ◽  
M. M. Bagheri-Mohagheghi
Keyword(s):  
Particle Size ◽  
Citric Acid ◽  
Structural Properties ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Alumina Nanoparticles ◽  
Complexing Agents ◽  
Gel Method ◽  
Sol Gel Method ◽  
Pechini Process

A sol-gel method based on the Pechini process was used to synthesize different phases of alumina nanoparticles using a polymeric precursor with Aluminum nitrate. The emphasis was on investigating the effect of two different complexing agents, urea and citric acid, on the structural properties, particle size, and phase transformation during the heat treatment that was studied by XRD, TEM, SEM, BET, and FT-IR spectroscopy. The obtained results showed that particles do get fused together at high temperatures, and also the size of particles increases with the increase of annealing temperature. It was concluded that the size ofα-alumina synthesized by urea was 10–15 nm, whereas the sample with citric acid yieldedα-powder with particle size of 200 nm. Also, the resulting powder prepared by urea exhibited larger surface area (84.2 m2/gm−1) compared to citric acid (39.92 m2/gm−1) at .

Annealing Effects on the Physical and Magnetic Properties of Tb1.5Y1.5Fe5O12 Films Nanoparticles Prepared by Sol-Gel Method

2013 ◽  
Vol 756 ◽  
pp. 91-98 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Annealing Temperature ◽  
Quartz Substrate ◽  
Sol Gel ◽  
Lattice Parameter ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Iron Garnet

Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900 °C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900°C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-raySpectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealingtemperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. Normal 0 21 false false false MS X-NONE X-NONE MicrosoftInternetExplorer4 Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900°C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900 °C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-ray Spectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealing temperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

Study on the Synthesis of Batches of the System Y-Ba-Cu-O Using Sol-Gel Method

2014 ◽  
Vol 91 ◽  
pp. 19-23
Author(s):  
Plamen Pashev ◽  
Rositsa Raykova ◽  
Yancho Hristov ◽  
Bogdan Bogdanov
Keyword(s):  
Particle Size ◽  
Citric Acid ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Blue Solution ◽  
Transformation Processes ◽  
Nitrate Solutions ◽  
Thermally Treated

The study presented deal with preparation of batches of the system Y-Ba-Cu-O using sol-gel method and citric acid as precursor. Batches with particle size of 100 nm containing each of the phases Y123 and Y211 were prepared. The stoichiometric amounts of Y, Ba and Cu oxides were dissolved in 65% HNO3 until clear blue solution was observed under heating to 80 ̊С. The nitrate solutions obtained were neutralized to pH = 6 with 25% solution of NH3 (p.a.), then С6Н8О7 was added as the gels obtained were thermally treated. The transformation processes taking place under change of temperature were studied by IR, XRD, DTA and SEM.

Effect of the annealing temperature and of Bi substitution on the structural and magnetic behaviors of double-doping (Bi/La, Ca) (La0.8Ca0.2)1−xBixFeO3 compounds

2020 ◽  
Vol 44 (23) ◽  
pp. 9813-9821
Author(s):  
H. Issaoui ◽  
A. Benali ◽  
M. Bejar ◽  
E. Dhahri ◽  
R. F. Santos ◽  
...  
Keyword(s):  
Citric Acid ◽  
Curie Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Double Doping

Perovskite (La0.8Ca0.2)1−xBixFeO3 compounds were synthesized by sol–gel method using the citric acid route and sintered at 800 °C and 900 °C. LCBFO 800 series has the smallest size of crystallites, a larger magnetization and a smaller Curie temperature.

Synthesis of LiV3O8 Crystallites via an Improved Citric Acid Assisted Sol-Gel Method

2012 ◽  
Vol 512-515 ◽  
pp. 227-230 ◽  
Author(s):  
Dun Qiang Wang ◽  
Li Yun Cao ◽  
Jian Feng Huang ◽  
Jian Peng Wu
Keyword(s):  
Particle Size ◽  
Citric Acid ◽  
Metal Ion ◽  
Sol Gel ◽  
Structure Stability ◽  
Ir Absorption ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
Sol Gel Method ◽  
Average Size

Lithium trivanadate (LiV3O8) powders have many attractive characteristics such as high specific energy density, good rate capacity and long cycle life due to their unique crystal structure and outstanding structure stability as cathode material for rechargeable lithium batteries. LiV3O8 crystallites were synthesized under different conditions via a combined ultrasonic irradiation and sol-gel method. The as-prepared LiV3O8 powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) absorption spectra. The thermal decomposition process was investigated using thermogravimetric (TG) and differential scanning calorimetry (DSC). The effects of molar ratios of metal ion/citric acid and calcinations temperature on phases and microstructure of the powders were investigated. Results indicate that calcinations temperatures have significant influence on the particle morphology, particle size and particle size distribution of the powders. The pure and rod-like LiV3O8 powders with an average size of 0.2-1 μm are obtained at 350 and 400 °C. With the increase of calcinations temperature, the powders exhibit preferred growth orientation along (100) planes. The crystallites obtained at 550 and 600 °C are composed by LiV3O8 with a small amount of Li0.3V2O5 phase, both of which exhibit tabular morphologies with an average size of 2-10 μm.

KNN-BF Lead-Free Piezoelectric Ceramics Synthesized by Sol-Gel Method

2015 ◽  
Vol 740 ◽  
pp. 3-6
Author(s):  
Guo Yuan Cheng ◽  
Xing Hua Fu ◽  
Xin Jin ◽  
Wen Hong Tao ◽  
Yu Qin Qiang
Keyword(s):  
Comparative Analysis ◽  
Citric Acid ◽  
Dielectric Loss ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Gel Method ◽  
Sol Gel Method ◽  
Metal Chelator

KNN-BF piezoelectric ceramics synthesized by sol-gel method in this experiment. By controlling bismuth and iron content in the system to study effects of them. We selected citric acid as metal chelator and ethylene glycol as esterification agent. PH maintained 5-6 during preparation of the sol. Sintering temperature of ceramic selected 1100°C. Preparation ceramics under these conditions and comparative analysis, the structure of ceramics is single perovskite and shap of crystals are square block. With the increase of x, properties of ceramics firstly increases and then decreases: d33, εr, Qm, Kpreaching the maximum, values of them were 136pC/N, 630(f =1KHz), 212, 0.41 respectively; dielectric loss to minimum is 0.07(f =1KHz); at this point, ceramics had best performance.

The Structural, Magnetic and Optical Properties of Ni-Mg-Zn Ferrite Prepared With Different Complexing Agents via Sol-Gel Method

2021 ◽  
Author(s):  
Yanchun Zhang ◽  
Aimin Sun ◽  
Zhaxi Suonan
Keyword(s):  
Optical Properties ◽  
Electron Microscope ◽  
Sol Gel ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Zn Ferrite ◽  
Vis Spectroscopy

Abstract Different complexing agents were used to prepare Ni-Mg-Zn ferrite with the composition formula Ni0.2Mg0.2Zn0.6Fe2O4 via sol-gel method, which included citric acid, oxalic acid, egg white and EDTA. The Ni0.2Mg0.2Zn0.6Fe2O4 ferrite with no complexing agent was also prepared as a comparison. The chemical phases of samples were analyzed by the X-ray diffraction (XRD), which indicated that samples had spinel phase structure. The lattice constants of samples are in the range of 8.3980 ~ 8.4089 Å. The composition and structure were further studied by fourier transform infrared spectroscopy (FTIR). There were two typical characteristic bands related to the stretching vibrations of spinel ferrite in FTIR spectra. Scanning electron microscope (SEM) micrographs and transmission electron microscope (TEM) images showed that the particles have the shape of spherical cube. Energy dispersive spectrometer (EDS) analyzed the elements and ingredients of samples, which included Ni, Mg, Zn, Fe and O. X-ray photoelectron spectroscopy (XPS) is used to examine further the elemental composition and chemical state of sample prepared with EDTA as complexing agent. The optical properties of samples were investigated by photoluminescence spectra and UV-Vis spectroscopy. Vibrating sample magnetometer (VSM) was used to characterize magnetic properties, hysteresis loops revealed the ferrimagnetism behavior of prepared samples.

Effect of annealing temperature on the structural and optical properties of ZnO thin films prepared by sol–gel method

Ionics ◽  
2010 ◽  
Vol 16 (9) ◽  
pp. 815-820 ◽  
Author(s):  
Yidong Zhang ◽  
Wenjun Fa ◽  
Fengling Yang ◽  
Zhi Zheng ◽  
Pingyu Zhang
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Zno Thin Films ◽  
Structural And Optical Properties ◽  
Gel Method ◽  
Sol Gel Method
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