Effect of grain size on the magnetic properties of superparamagnetic Ni0.5Zn0.5Fe2O4 nanoparticles by co-precipitation process

2011 ◽  
Vol 323 (12) ◽  
pp. 1717-1721 ◽  
Author(s):  
D.G. Chen ◽  
X.G. Tang ◽  
J.B. Wu ◽  
W. Zhang ◽  
Q.X. Liu ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Precipitation Process ◽  
Co Precipitation

Consolidation and properties of Gd0.1Ce0.9O1.95 nanoparticles for solid-oxide fuel cell electrolytes

2006 ◽  
Vol 21 (1) ◽  
pp. 119-124 ◽  
Author(s):  
A.I.Y. Tok ◽  
L.H. Luo ◽  
F.Y.C. Boey ◽  
J.L. Woodhead
Keyword(s):  
Grain Size ◽  
Ionic Conductivity ◽  
Sintering Temperature ◽  
Spherical Shape ◽  
Impedance Analysis ◽  
Lattice Parameter ◽  
Narrow Particle Size Distribution ◽  
Precipitation Process ◽  
Boundary Area ◽  
Co Precipitation

Gd-doped ceria solid solutions have been recognized to be leading electrolytes for use in intermediate-temperature fuel cells. In this paper, the preparation, solubility, and densification of Gd0.1Ce0.9O1.95 ceramics derived from carbonate co-precipitation are reported. The dissolution of Gd2O3 in CeO2 lattice was identified to be completed during the co-precipitation process by studying the lattice parameter as a function of temperature. After calcination at 800 °C for 2 h, the nano-sized Gd0.1Ce0.9O1.95 powder (∼33 nm) with a nearly spherical shape and a narrow particle-size distribution was obtained. This calcined powder has high sinterability and maximum densification rate at ∼1000 °C. Sintering at 1300 °C for 4 h yielded over 97% relative density with near maximum. The grain size increased with increases in sintering temperature. The ionic conductivity of these pellets was tested by alternating current impedance spectroscopy to elucidate the contribution of intragranular and intergranular conductivity to the total ionic conductivity. It was found that sintering temperature does not affect intragranular conductivity, though intergranular conductivity was strongly influenced by grain size, grain boundary area, and relativity density. This pellet sintered at 1500 °C for 4 h showed a high ionic conductivity of 5.90 × 10−2 s/cm when measured at 750 °C. The characterization and structural evaluation of the as-received powders were carried out using x-ray diffraction, transmission electron microscopy, Brunauer–Emmett–Teller, and dilatometer and impedance analysis.

Dielectric and magnetic properties of BaTiO3/Ni0.5Zn0.5Fe2O4 composite ceramics synthesized by a co-precipitation process

2014 ◽  
Vol 614 ◽  
pp. 289-296 ◽  
Author(s):  
Pengli Zhu ◽  
Qi Zheng ◽  
Rong Sun ◽  
Wenjie Zhang ◽  
Jihua Gao ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Precipitation Process ◽  
Composite Ceramics ◽  
Co Precipitation

Structural, Optical and Magnetic Properties of Zn1-xCoxO Nanoparticles

2020 ◽  
Vol 20 (9) ◽  
pp. 5525-5532
Author(s):  
P. Shunmuga Sundaram ◽  
G. Arivazhagan ◽  
S. S. R. Inbanathan ◽  
Shamima Hussian ◽  
E. Manikandan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Precipitation Process ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
Lattice Constants ◽  
Optical And Magnetic Properties ◽  
Co Precipitation ◽  
Average Bond ◽  
True Values ◽  
Density Results

Zn1−xCoxO nanoparticles with three different values of ‘x’ (x = 0.05, 0.10, 0.15) were prepared by chemical co-precipitation process without any further heat treatment. The X-ray diffraction studies confirmed the wurtzite hexagonal crystal structure for synthesized Zn1−xCoxO nanoparticles. The dislocation density results reveal that there is an increase in the concentration of lattice imperfections with increasing the concentration of Co ions. The true values of lattice constants were calculated by using Nelson–Riley Function (NRF). Further, the average bond length (BL) were also calculated and presented. The optical and magnetic properties of Zn1−xCoxO nanoparticles were examined by room-temperature photoluminescence (PL) spectroscopy and vibrating sample magnetometer (VSM), respectively. The calculated values of magnetic susceptibility for Zn1−xCoxO nanoparticles with x = 0.05, 0.10, 0.15 were found to be 9.883×10−4, 2.29×10−2 and 2.37×10−2, respectively.

Effect of Grain Size on Structural and Magnetic Properties of CuFe$_{2}$O$_{4}$ Nanograins Synthesized by Chemical Co-Precipitation

2012 ◽  
Vol 48 (5) ◽  
pp. 1839-1843 ◽  
Author(s):  
S. Manjura Hoque ◽  
S. S. Kader ◽  
D. P. Paul ◽  
D. K. Saha ◽  
H. N. Das ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Structural And Magnetic Properties ◽  
Co Precipitation

Effect of Grain Size on the Luminescent Properties of Nano-Scale Gd2O3:Eu

2005 ◽  
Vol 23 ◽  
pp. 15-18 ◽  
Author(s):  
Qing Feng Liu ◽  
Qian Liu
Keyword(s):  
Grain Size ◽  
Luminescent Properties ◽  
Combustion Method ◽  
Lattice Parameter ◽  
Precipitation Process ◽  
Micro Scale ◽  
Grain Sizes ◽  
Nano Scale ◽  
Co Precipitation ◽  
Uv Excitation

Nano-scale Gd2O3:Eu phosphor powders were synthesized by combustion method. In this process, the grain sizes of nano-scale Gd2O3:Eu were controlled by changing the amount of citric acid. Compared with micro-scale powders obtained from co-precipitation process, XRD revealed that the lattice parameter of nano-scale powders Gd2O3:Eu decreased. Further detailed study show that the luminescent properties were related to the grain size of nano Gd2O3:Eu powders under UV excitation.

scholarly journals Impact of Iron on the Fe–Co–Ni Ternary Nanocomposites Structural and Magnetic Features Obtained via Chemical Precipitation Followed by Reduction Process for Various Magnetically Coupled Devices Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 341
Author(s):  
Tien Hiep Nguyen ◽  
Gopalu Karunakaran ◽  
Yu.V. Konyukhov ◽  
Nguyen Van Minh ◽  
D.Yu. Karpenkov ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Reduction Process ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Magnetic Characteristics ◽  
Reduction Temperature ◽  
Fe Content ◽  
Magnetic Features ◽  
Co Precipitation

This paper presents the synthesis of Fe–Co–Ni nanocomposites by chemical precipitation, followed by a reduction process. It was found that the influence of the chemical composition and reduction temperature greatly alters the phase formation, its structures, particle size distribution, and magnetic properties of Fe–Co–Ni nanocomposites. The initial hydroxides of Fe–Co–Ni combinations were prepared by the co-precipitation method from nitrate precursors and precipitated using alkali. The reduction process was carried out by hydrogen in the temperature range of 300–500 °C under isothermal conditions. The nanocomposites had metallic and intermetallic phases with different lattice parameter values due to the increase in Fe content. In this paper, we showed that the values of the magnetic parameters of nanocomposites can be controlled in the ranges of MS = 7.6–192.5 Am2/kg, Mr = 0.4–39.7 Am2/kg, Mr/Ms = 0.02–0.32, and HcM = 4.72–60.68 kA/m by regulating the composition and reduction temperature of the Fe–Co–Ni composites. Due to the reduction process, drastic variations in the magnetic features result from the intermetallic and metallic face formation. The variation in magnetic characteristics is guided by the reduction degree, particle size growth, and crystallinity enhancement. Moreover, the reduction of the surface spins fraction of the nanocomposites under their growth induced an increase in the saturation magnetization. This is the first report where the influence of Fe content on the Fe–Co–Ni ternary system phase content and magnetic properties was evaluated. The Fe–Co–Ni ternary nanocomposites obtained by co-precipitation, followed by the hydrogen reduction led to the formation of better magnetic materials for various magnetically coupled device applications.

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