Synthesis of Sr-Hexaferrite Nano-Powder by Sol-Gel Auto-Combustion Process with Addition of Organic Matters into Precursor Solution

2009 ◽  
Author(s):  
M. G. Hasab ◽  
S. A. S. Ebrahimi ◽  
A. Badiei ◽  
Kh. Ranjbar ◽  
Mohamad Rusop ◽  
...  
Keyword(s):  
Sol Gel ◽  
Combustion Process ◽  
Precursor Solution ◽  
Organic Matters ◽  
Nano Powder ◽  
Auto Combustion

AN INVESTIGATION ON THE FORMATION OF STRONTIUM HEXAFERRITE NANO-POWDER BY A SOL-GEL AUTO-COMBUSTION METHOD IN THE PRESENCE OF SURFACTANT USING DIFFERENT BASIC AGENTS

2008 ◽  
Vol 22 (18n19) ◽  
pp. 3159-3164 ◽  
Author(s):  
S. ALAMOLHODA ◽  
S. A. SEYYED EBRAHIMI ◽  
A. BADIEI
Keyword(s):  
Sol Gel ◽  
Combustion Process ◽  
Average Crystallite Size ◽  
Combustion Method ◽  
Strontium Hexaferrite ◽  
Line Broadening ◽  
Hard Magnetic Material ◽  
Nano Powder ◽  
Auto Combustion ◽  
Scherrer Formula

Strontium hexaferrite is a hard magnetic material and has been extensively used as a permanent magnet. In this work a novel sol-gel auto-combustion method was used to synthesize ultra fine strontium hexaferrite. The investigations show that the model of combustion changes with the change of basic agent. The XRD results show that using ammonia or trimethylamine does not change the composition of the combustion product and it also shows that the surfactant burns completely during the combustion process. The average crystallite size of hexaferrite powders was also measured by X-ray line broadening technique employing Scherrer formula. The results show that changing the basic agent makes the particle size of the final product much smaller. Basic agent also affects the formation temperature of the single phase strontium hexaferrite.

INFLUENCE OF pH ON PHYSICAL PROPERTIES OF NICKEL-ZINC NANOCRYSTALLINE POWDERS SYNTHESIZED BY A SOL-GEL AUTO-COMBUSTION METHOD

2008 ◽  
Vol 22 (18n19) ◽  
pp. 3153-3158 ◽  
Author(s):  
M. R. BARATI ◽  
S. A. SEYYED EBRAHIMI ◽  
A. BADIEI
Keyword(s):  
Crystallite Size ◽  
Zinc Ferrite ◽  
Ph Value ◽  
Sol Gel ◽  
Combustion Process ◽  
Nanocrystalline Powders ◽  
Nanocrystalline Powder ◽  
Nickel Zinc ◽  
Auto Combustion ◽  
Influence Of Ph

In this research a sol-gel auto-combustion route has been proposed to synthesize nickel-zinc ferrite nanocrystalline powder, using metal nitrates, citric acid as fuel and ammonia as pH adjusting agent. The influence of pH value of the solution on phase evolution, crystallite size and morphology of as-burnt powders were investigated by XRD, SEM and TEM techniques. The results revealed that with pH=7 the single phase nickel-zinc ferrite nanocrystalline powders with crystallite size of about 27nm were formed directly after auto combustion process.

IMPROVED MAGNETIC PROPERTIES OF Sm COMBINING Co OR/AND Zn SUBSTITUTED BARIUM M-TYPE HEXAFERRITES

2012 ◽  
Vol 26 (26) ◽  
pp. 1250141 ◽  
Author(s):  
Y. B. HAN ◽  
J. SHA ◽  
L. N. SUN ◽  
Q. TANG ◽  
Q. LU ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
Magnetocrystalline Anisotropy ◽  
Sol Gel ◽  
Combustion Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barium Hexaferrites ◽  
Auto Combustion ◽  
Magnetic Dilution

Sm (Co or/and Zn) substituted nanocrystalline barium hexaferrites were synthesized by the sol–gel auto-combustion process, then X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) were used to characterize and discuss the phase composition and the magnetic properties of the as-prepared barium hexaferrites. All results showed that the phase composition and magnetic properties were closely related to the doping elements and x. Owing to hyperfine field, canting spin, magnetic dilution and impurity phases, the saturation magnetization (Ms) of all samples increased firstly, and then decreased. Considering the crystallization, the magnetocrystalline anisotropy and the ions occupancy, the doping elements and x critically affected the coercivity (Hc). Compared the magnetic properties of all the samples, it is concluded that Zn 2+ and Co 2+ influenced each other and Zn 2+ occupied 4f2 sites prior to Co 2+, which led to the increase of Ms and the decrease of Hc.

Effects of different sintering temperature on structural and magnetic properties of Ni–Cu–Co ferrite nanoparticles

2018 ◽  
Vol 32 (27) ◽  
pp. 1850321 ◽  
Author(s):  
Xiaoguang Pan ◽  
Aimin Sun ◽  
Yingqiang Han ◽  
Wei Zhang ◽  
Xiqian Zhao
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Spinel Structure ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Stable State ◽  
Precursor Solution ◽  
Auto Combustion ◽  
Different Temperatures ◽  
Ft Ir

In this work, sol–gel auto-combustion technology is used to synthesize nanocrystalline Ni[Formula: see text]Cu[Formula: see text]Co[Formula: see text]Fe2O4 with high purity metal nitrate and citric acid as precursor solution. The prepared samples are sintered at different temperatures (400[Formula: see text]C, 500[Formula: see text]C, 600[Formula: see text]C, 700[Formula: see text]C, 800[Formula: see text]C, 900[Formula: see text]C, 1000[Formula: see text]C and 1100[Formula: see text]C) for 3.5 h. The structure and magnetic properties of the samples are characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and vibrating sample magnetometer (VSM). The analysis of the XRD patterns confirms that all the samples have a single-phase cubic spinel structure. The particle size of the prepared samples (between 23 nm and 36 nm) is determined by the Scherrer equation. The effect of particle size is through observation of samples sintered at different temperatures. FT-IR spectroscopy shows the characteristic peak is near 588 cm[Formula: see text]. And the measurement also confirms the formation of spinel structure. The magnetic parameters of the samples are measured by VSM at room temperature with a maximum magnetic field of 1 T. Coercivity, remanent magnetization and saturation magnetization change with the changing sintering temperature. It can be clearly observed that the magnetic properties increase significantly with the temperature increasing from 600[Formula: see text]C to 700[Formula: see text]C. The dM/dH versus H curves are obtained by differentiating the hysteresis loop. The increasing peak height of dM/dH at [Formula: see text], indicates a magnetically stable state for the samples with good crystalline cubic spinel structure.

Facile Synthesis and Microwave-Absorption Properties of Organic–Inorganic CoFe2O4/Polyaniline Nanocomposites with Embedded Structure

2020 ◽  
Vol 20 (3) ◽  
pp. 1756-1764 ◽  
Author(s):  
Peng Chen ◽  
Lin-Wen Jiang ◽  
Shan-Shan Yang ◽  
Hong-Bing Chen ◽  
Jun He ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Oxidative Polymerization ◽  
Sol Gel ◽  
Combustion Process ◽  
Interfacial Polarization ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Auto Combustion ◽  
Embedded Structure

Organic–inorganic CoFe2O4/polyaniline (CoFe2O4/PA) nanocomposites with embedded structures were synthesized by combining the sol–gel auto-combustion process and in-situ oxidative polymerization. The phases and morphologies of the prepared samples were identified. The pure CoFe2O4 samples exhibited inferior microwave-absorption properties in a frequency range of 2–18 GHz. Upon the incorporation of PA, the formed CoFe2O4/PA nanocomposites exhibited rather good absorption performances. When the sample thickness was 2.5 mm, the maximum reflection loss (RL) reached -22.3 dB, while the RL below -10 dB corresponded to the range of 11.0–17.1 GHz, which contains almost the entire Ku-band, making the structure promising for commercial and military applications. A physical model was employed to explain the effects of the embedded structure on the microwave-absorption performances. The excellent microwave-absorption performances could be attributed to the interfacial polarization and repeated reflection of the microwaves inside the CoFe2O4/PA composite.

scholarly journals Structural, impedance and Mössbauer studies of magnesium ferrite synthesized via sol–gel auto-combustion process

2017 ◽  
Vol 21 (8) ◽  
pp. 899-910 ◽  
Author(s):  
Shahid Khan Durrani ◽  
Sumaira Naz ◽  
Mazhar Mehmood ◽  
Muhammad Nadeem ◽  
Muhammad Siddique
Keyword(s):  
Sol Gel ◽  
Combustion Process ◽  
Magnesium Ferrite ◽  
Mössbauer Studies ◽  
Auto Combustion
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