Structure, Magnetic Properties and Defects Distribution of Mn0.5Zn0.5LaxFe2-xO4 Nanocrystals

2010 ◽  
Vol 105-106 ◽  
pp. 706-708
Author(s):  
Li Qun Wang
Keyword(s):  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Positron Annihilation Lifetime ◽  
Zn Ferrite ◽  
Mean Grain Size ◽  
Sol Gel Process ◽  
La Substitution ◽  
The Mean

La-substitution Mn-Zn ferrite nanocrystals, Mn0.5Zn0.5LaxFe2-xO4 (x=0.00, 0.05, 0.10, 0.15, 0.20) were prepared by sol-gel process. X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and positron annihilation lifetime spectroscopy (PALS) studies were carried out. The result of XRD suggests that the mean grain size decreases from 63.8 nm to 44.6 nm with the increment of La-substitution concentration from x=0.00 to 0.20. The VSM measurement shows that the saturation magnetization (MS) increases in the range of x<0.10, then it drastically decreases in the range of 0.10<x<0.20. At last, defects property is discussed using PALS.

Structural and Magnetic Properties of Ni0.5Zn0.5Fe2O4 Synthesized through the Sol-Gel Method

2014 ◽  
Vol 664 ◽  
pp. 75-79
Author(s):  
Beh Hoe Guan ◽  
Muhammad Hanif Zahari ◽  
Lee Kean Chuan
Keyword(s):  
Magnetic Properties ◽  
Calcination Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Calcination Temperatures ◽  
Zn Ferrite

This study investigates the influence of calcination temperatures on the magnetic properties of Ni0.5Zn0.5Fe2O4(Ni-Zn) ferrites.Ni-Zn ferrite with the chemical formula Ni0.5Zn0.5Fe2O4was prepared from their respective nitrate salts through the sol-gel method. The resulting ferrites were characterized using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM). Single phased Ni0.5Zn0.5Fe2O4 was obtained at all calcination temperatures.FESEM Micrographs reveals an increase in the grain size with the increase of the calcination temperature. Consequently, the magnetic saturation of the samples were found to increase with each increase in the calcination temperature where the highest value obtained is 70.58 emu/g for the samples calcined at 1000°C.

Effect of Annealing temperature on the Structural and Magnetic Properties of TbxY3-xFe5O12(x = 0.0, 1.0, 2.0) Thin Films Prepared by Sol-Gel Process

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Garnet Phase ◽  
Sol Gel Process ◽  
Amorphous Structures

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.

scholarly journals Preparation of high-entropy carbides by different sintering techniques

2021 ◽  
Vol 56 (19) ◽  
pp. 11237-11247 ◽  
Author(s):  
Johannes Pötschke ◽  
Manisha Dahal ◽  
Mathias Herrmann ◽  
Anne Vornberger ◽  
Björn Matthey ◽  
...  
Keyword(s):  
Grain Size ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Vacuum Sintering ◽  
X Ray ◽  
High Entropy ◽  
Mean Grain Size ◽  
The Mean ◽  
Gas Pressure Sintering ◽  
Hardness Values

AbstractDense (Hf, Ta, Nb, Ti, V)C- and (Ta, Nb, Ti, V, W)C-based high-entropy carbides (HEC) were produced by three different sintering techniques: gas pressure sintering/sinter–HIP at 1900 °C and 100 bar Ar, vacuum sintering at 2250 °C and 0.001 bar as well as SPS/FAST at 2000 °C and 60 MPa pressure. The relative density varied from 97.9 to 100%, with SPS producing 100% dense samples with both compositions. Grain size measurements showed that the substitution of Hf with W leads to an increase in the mean grain size of 5–10 times the size of the (Hf, Ta, Nb, Ti, V,)C samples. Vacuum-sintered samples showed uniform grain size distribution regardless of composition. EDS mapping revealed the formation of a solid solution with no intermetallic phases or element clustering. X-ray diffraction analysis showed the structure of mostly single-phase cubic high-entropy carbides. Hardness measurements revealed that (Hf, Ta, Nb, Ti, V)C samples possess higher hardness values than (Ta, Nb, Ti, V, W)C samples.

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

Sol-Gel derived Bi4-xNdxTi3O12 Thin Films and Their Characterization

2002 ◽  
Vol 737 ◽  
Author(s):  
R.E. Melgarejo ◽  
M.S. Tomar ◽  
A. Hidalgo ◽  
R.S. Katiyar
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complete Solid Solution ◽  
Sol Gel Process ◽  
Ferroelectric Memory ◽  
Initial Results

ABSTRACTNd substituted bismuth titanate Bi4-xNdxTi3O12 were synthesized by sol-gel process and thin films were deposited on Pt substrate (Pt/TiO2/SiO2/Si) by spin coating. Thin films, characterized by X-ray diffraction and Raman spectroscopy, shows complete solid solution up to the composition x < 1. Initial results indicate that the ferroelectric polarization increases with increasing Nd content in the film with 2Pr = 50μC/cm2 for x = 0.46, which may have application in non-volatile ferroelectric memory devices.

Study on optical and magnetic properties of FexNi1-xMn2O4 materials

2021 ◽  
Vol 66 (1) ◽  
pp. 57-64
Author(s):  
Hang Pham Vu Bich ◽  
Yen Nguyen Hai ◽  
Mai Phung Thi Thanh ◽  
Dung Dang Duc ◽  
Hung Nguyen Manh ◽  
...  
Keyword(s):  
Single Phase ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
Raman Scattering Spectrum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scattering Spectrum ◽  
Diffraction Diagram ◽  
Optical And Magnetic Properties ◽  
Scanning Electron

In this study, we present the process of synthesis FexNi1-xMn2O4 (x = 0; 0.1; 0.3; 0.5; 0.7; 0.9; 1) by method sol-gel. Scanning electron microscope results shows that the particle size is about 50 nm. The X-ray diffraction diagram shows that the samples are single phase, changing structure clearly as the x ratio increases from 0 to 1. The lattice constant, the bond length also changes with x-value as shown on the Raman scattering spectrum. The results of the vibrating sample magnetometer show that the magnetism of the material FexNi1-xMn2O4 changes with the value of x and reaches a maximum in the range x from 0.5 to 0.7.

Synthesis and Characterizations of Strontium Substituted Hydroxyapatite Thin Films

2010 ◽  
Vol 93-94 ◽  
pp. 231-234
Author(s):  
B. Hongthong ◽  
Satreerat K. Hodak ◽  
Sukkaneste Tungasmita
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Composition ◽  
Spin Coating ◽  
Phase Structure ◽  
Sol Gel ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process

Strontium substituted hydroxyapatite(SrHAp) were fabricated both in the form of powder as reference and thin film by using inorganic precursor reaction. The sol-gel process has been used for the deposition of SrHAp layer on stainless steal 316L substrate by spin coating technique, after that the films were annealed in air at various temperatures. The chemical composition of SrHAp is represented (SrxCa1-x)5(PO4)3OH, where x is equal to 0, 0.5 and 1.0. Investigations of the phase structure of SrHAp were carried out by using X-ray diffraction technique (XRD). The results showed that strontium is incorporated into hydroxyapatite where its substitution for calcium increases in the lattice parameters, and Sr3(PO4)2 can be detected at 900°C. The SEM micrographs showed that SrHAp films exhibited porous structure before develop to a cross-linking structure.

Low-Temperature Synthesis of Nano-Crystalline ZnTiO3 Powders by Aqueous Sol-Gel Process

2014 ◽  
Vol 543-547 ◽  
pp. 3741-3744
Author(s):  
Quan Jing Mei ◽  
Cong Ying Li ◽  
Jing Dong Guo ◽  
Gui Wang ◽  
Hai Tao Wu
Keyword(s):  
Sol Gel ◽  
Zinc Nitrate ◽  
X Ray Diffraction ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Calcination Process ◽  
X Ray ◽  
Nano Crystalline ◽  
Transmission Electron ◽  
Sol Gel Process

The ecandrewsite-type ZnTiO3was successfully synthesized by the aqueous sol-gel method using TiO2dioxide and zinc nitrate as starting materials instead of expensive organic solvent and metal alkoxides. The as-prepared nanopowders were characterized by X-ray diffraction (XRD), differential thermal analysis (DTA) and transmission electron microscopy (TEM), respectively. The results showed that the calcination process of gel consisted of a series of oxidation and combustion reactions, accompanied by significantly exothermal effects. Highly reactive nanosized ZnTiO3powders were successfully obtained at 850 °C with particle size ~50 nm. By comparison, the aqueous sol-gel process was the most effective and least expensive technique used for the preparation of ZnTiO3nanopowders.

Preparation of YBCO Superconducting Films by Sol-Gel Process

2007 ◽  
Vol 546-549 ◽  
pp. 2007-2010
Author(s):  
Gao Yang Zhao ◽  
Huang Li Zhang ◽  
Ren Zhong Xue ◽  
Yuan Qing Chen ◽  
Li Lei
Keyword(s):  
Sol Gel ◽  
Precursor Solution ◽  
Superconducting Films ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
Organic Salts ◽  
Ybco Films ◽  
X Ray ◽  
Sol Gel Process ◽  
Ybco Superconducting Films

precursor solution was prepared using barium trifluoroacetae (Ba-TFA) and non-fluorine yttrium (Y) and copper (Cu) organic salts. The precursor solution was modified by benzalacetone (BzAcH), in which the Cu2+ were chelated with BzAcH, which preventing the loss of Cu in the pyrolysis process. Dense YBCO superconducting films with smooth surface, which confirmed by scanning electron microscopy (SEM), were repeatedly obtained through sol-gel process. X-ray diffraction (XRD) 2θ scanning and φ scanning indicated that the as-prepared YBCO films had good c-axis texture. YBCO films with superconducting transition temperature (TC) above 89K were obtained.

Study on the Synthesis of Nano-Crystalline Mg2SiO4 Powders by Aqueous Sol-Gel Process

2013 ◽  
Vol 538 ◽  
pp. 142-145 ◽  
Author(s):  
X.F. Chen ◽  
J. Li ◽  
T.T. Feng ◽  
Y.S. Jiang ◽  
X.H. Zhang ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Sol Gel ◽  
Magnesium Nitrate ◽  
Metal Alkoxides ◽  
X Ray Diffraction ◽  
Calcination Process ◽  
X Ray ◽  
Nano Crystalline ◽  
Sol Gel Process ◽  
Scanning Electron

The forsterite-structure Mg2SiO4 was successfully synthesized by the aqueous sol-gel method using Si sols dioxide and magnesium nitrate as starting materials instead of expensive organic solvent and metal alkoxides. The as-prepared nanopowders were characterized by X-ray diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscope (SEM), respectively. The results showed that the calcination process of gel consisted of a series of oxidation and combustion reactions, accompanied by significantly exothermal effects. Highly reactive nanosized Mg2SiO4 powders were successfully obtained at 850 °C with particle size of 60~80 nm.

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