Dielectric Characteristics of Donor Doped Nonlead Ba(Cu1/3Nb2/3)O3 Perovskite Material Synthesized by Microwave-assisted Citrate-nitrate Sol-gel Route

2007 ◽  
Vol 997 ◽  
Author(s):  
Alp Manavbasi ◽  
Jeffrey C LaCombe
Keyword(s):  
Sol Gel ◽  
Particle Morphology ◽  
Ferroelectric Ceramic ◽  
Copper Nitrate ◽  
Correlation Spectroscopy ◽  
Nanocrystalline Powders ◽  
Microwave Assisted ◽  
Precursor Material ◽  
Auto Combustion ◽  
Diffraction Patterns

AbstractNonlead perovskite type, Ba(Cu1/3Nb2/3−xWx)O3 (x = 0, 0.025), ferroelectric ceramic powders (BCN) were prepared by the microwave-assisted citrate-nitrate sol-gel technique. The gel was formed from a stable and homogeneous sol prepared by mixing stable solutions of barium- and copper-nitrate, tungsten citrate, and peroxo-citrato-niobium precursors. Microwave irradiation of the gel resulted in a dark, fluffy precursor material after auto-combustion. Calcination of the as-combusted samples produces a single phase with tetragonal splitting in X-Ray diffraction patterns. The crystallite size of the synthesized samples was found to be 41 nm. Particle morphology and the size of nanocrystalline powders were characterized by scanning electron microscopy and photon correlation spectroscopy, respectively. Electrical and dielectric properties of sintered samples were investigated by impedance spectroscopy. The isothermal ac measurements were performed from room temperature, up to 600 °C for W6+ doped and undoped BCN samples.

One-step synthesis of barium hexaferrite nano-powders via microwave-assisted sol–gel auto-combustion

2010 ◽  
Vol 30 (4) ◽  
pp. 993-997 ◽  
Author(s):  
Liu Junliang ◽  
Zeng Yanwei ◽  
Guo Cuijing ◽  
Zhang Wei ◽  
Yang Xiaowei
Keyword(s):  
Sol Gel ◽  
Barium Hexaferrite ◽  
Microwave Assisted ◽  
Auto Combustion ◽  
One Step

Obtaining of the Ir-Al Nanocrystalline Powders by Mechanical Alloying

2011 ◽  
Vol 672 ◽  
pp. 171-174
Author(s):  
Ionel Chicinaş ◽  
P. Cârlan ◽  
Florin Popa ◽  
Virgiliu Călin Prică ◽  
Lidia Adriana Sorcoi
Keyword(s):  
Mechanical Alloying ◽  
Particle Morphology ◽  
High Energy ◽  
Atomic Ratio ◽  
Planetary Mill ◽  
Nanocrystalline Powders ◽  
Alloy Formation ◽  
X Ray Diffraction ◽  
Chemical Homogeneity ◽  
Diffraction Patterns

The Ir-Al powder in the 1:1 atomic ratio was obtained by high energy mechanical alloying in a Pulverisette 4 Fritch planetary mill. The final product was obtained after 28 h of milling in argon atmosphere. Alloy formation was investigated by X-ray diffraction. After 4 h of milling the new structure of IrAl compound is found in the diffraction patterns. The obtained powders are nanocrystalline with a mean crystallite size of 11 nm after 28 h of milling. The particle morphology and the chemical homogeneity were studied using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDX). It was found that the obtained compound present large particles composed by smaller one.

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.

Synthesis of (Ba,Ti)-Doped Apatite-Type Lanthanum Silicate Nano-Sized Powders via Microwave-Assisted Sol-Gel Auto-Combustion Route

2013 ◽  
Vol 652-654 ◽  
pp. 882-885 ◽  
Author(s):  
Ran Wu ◽  
Jia Mei Ye ◽  
Qi Zhao Li ◽  
Sheng Yun Wang ◽  
Xiu Lei Chen ◽  
...  
Keyword(s):  
Particle Size ◽  
Citric Acid ◽  
Sol Gel ◽  
Lanthanum Nitrate ◽  
Microwave Assisted ◽  
Auto Combustion ◽  
Combustion Route ◽  
Lanthanum Silicate ◽  
Apatite Type

In this paper, (Ba,Ti)-doped lanthanum silicate nano-sized powders have been synthesized via microwave assisted sol-gel auto-combustion route by using TEOS and lanthanum nitrate as the starting materials, citric acid and glycol as chelators. Both the phase compositions and morphologies of the obtained powders have been characterized. The results indicated that: the synthesized nano powders were characterized as fluffy aggregates with the particle size ranging from 50 to 100nm. As the doping contents of Ba increased, the crystalline sizes decreased and the aggregation were deteriorated, while the particle size decreased from 120nm to 80nm and the aggregation between particles were halted as the doping contents of Ti increased.

scholarly journals Magnetic properties of Cu and Al doped nano BaFe12O19 ceramics

2020 ◽  
Vol 10 (3) ◽  
pp. 5455-5459
Keyword(s):  
Saturation Magnetization ◽  
Single Phase ◽  
Sol Gel ◽  
Hexagonal Structure ◽  
Magnetic Characteristics ◽  
X Ray Diffraction ◽  
Cu Substitution ◽  
Auto Combustion ◽  
Diffraction Patterns ◽  
Combustion Technique

The BaCuxFe12-xO19 and BaAlxFe12-xO19 (x = 0.0, 0.4, 0.8, 1.2) materials were prepared via sol-gel auto combustion technique. Further, the X-ray diffraction patterns suggested the formation of single phase hexagonal structure. This work is aimed to study the effect of diamagnetic and paramagnetic elements on magnetic characteristics of BaFe12O19. The results established that in the case of diamagnetic (Cu) substitution, the saturation magnetization was increased and decreased alternatively. Furthermore, it was noticed that the coercivity values of all doped samples were lower than those of undoped samples. But the replacement of Fe3+ with paramagnetic (Al) element led to a decrease in saturation magnetization and to a significant increase in the coercive field.

Synthesis and study of Co doped Ni-Cd ferro-spinels by microwave assisted sol-gel auto-combustion method

2020 ◽  
Vol 555 (1) ◽  
pp. 146-160
Author(s):  
H. S. Ahamad ◽  
K. G. Rewatkar ◽  
N. S. Meshram ◽  
S. J. Dhoble
Keyword(s):  
Sol Gel ◽  
Combustion Method ◽  
Microwave Assisted ◽  
Auto Combustion ◽  
Co Doped
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