Preparation, Morphological and Structural Properties of Nanocrystalline Ni-Mg Cobalt-Ferrite Synthesized by the Co-Precipitation Method

2015 ◽  
Vol 1109 ◽  
pp. 355-359 ◽  
Author(s):  
Rizuan Mohd Rosnan ◽  
Zulkafli Othaman ◽  
Ali A. Ati

The present study describes the morphological and structural characterization of nanosized Ni-Mg cobalt-ferrites. The nominal compositions Co0.5Ni0.5−xMgx Fe2O4 in the range (0.0 ≤ x ≤ 0.5) have been synthesized by co-precipitation method. These nanopowder products were sintered in furnace at temperature of 900°C for 10 hour with a heating rate of 5°C/min to obtain these ferrites. The prepared nanoferrites were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) with varying concentration (x) in the composition of the prepared nanoferrites. XRD confirmed formation of single phase spinel ferrite with average crystalline size in the range of 34–37 nm. Lattice constant (a) increases with an increase of Mg concentration. Further information about the structure and morphology of the nanoferrites was obtained from FESEM and results are in good agreement with XRD.

Author(s):  
R. M. Rosnan ◽  
Zulkafli Othman ◽  
A. A. Ati

This study evaluates the morphology and structural properties of Ni-Mg substituted Cobalt ferrite samples prepared through the co-precipitation method. The nominal composition of Co0.5Ni0.5−xMgx Fe2O4 in the range x = 0.1 have been synthesized and then were sintered at temperature 700 and 1000°C for 10 hour with a heating rate of 5°C/min. The prepared nano-ferrites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). XRD confirmed formation of single phase spinel ferrite with average crystalline size in the range of 40–120 nm. Further information about the structure and morphology of the nanoferrites was obtained from FESEM and results are in good agreement with XRD.


2016 ◽  
Vol 846 ◽  
pp. 352-357 ◽  
Author(s):  
Rizuan Mohd Rosnan ◽  
Zulkafli Othaman ◽  
Ali A. Ati ◽  
Rosli Hussin ◽  
Shadab Dabagh ◽  
...  

This study evaluates the structural and magnetic properties of Ni-Mg substituted Cobalt ferrite samples prepared through the co-precipitation method. The nominal compositions Co0.5Ni0.5−xMgx Fe2O4 in the range x = 0.1 have been synthesized and then was sintered at temperature at 700 and 1000°C in the furnace for 10 hour with a heating rate of 5°C/min. The prepared nanoferrites were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibration sample magnetometer (VSM). XRD confirmed formation of single phase spinel ferrite with average crystalline size in the range of 27–33 nm. The lattice constant (a), cell volume (V) and X-ray density (ρx) are also calculated from XRD data. Lattice constant (a) decreases with an increase of sintering temperature. Further information about the structure and morphology of the nanoferrites was obtained from FESEM and results are in good agreement with XRD. Saturation magnetization showed increasing trend with sintering temperature from 700 to 1000°C.


Author(s):  
Ali A. Ati ◽  
Zulkafli Othaman ◽  
Shadab Dabagh ◽  
R. M. Rosnan ◽  
Samad Zare

Nano crystalline powders of Co-Ni ferrite compounds having the chemical formula Co(x)Ni(1-x) Fe2O4( x = 0.0, 0.2 and 1.0) have been successfully synthesized by co-precipitation technique. These synthesized compounds are characterized by X-ray diffraction (XRD), field emission scan electron microscopy (FESEM), fourier transformed infrared (FTIR) spectrum, energy dispersive X-ray diffraction (EDX) and TGA-DTA. The XRD analyses of the samples sintered at 600 °C clearly show the formation of single cubic spinel structure. XRD patterns are further analyzed to calculate the lattice constant and jump length of charge carriers. Average crystalline sizes for ferrite powders are determined from XRD line using Debye-Scherrer's formula is found to be in the range of 16 to 19 nm with narrow size distribution. The Fourier transformed infrared (FTIR) spectrum characterization of the  spinel ferrite structure sintered at 600 °C shows two fundamental strong band in the range 385-600 cm-1, which is attributed to different main metal-oxygen bands.


2010 ◽  
Vol 93-94 ◽  
pp. 153-156 ◽  
Author(s):  
Pusit Pookmanee ◽  
Sumintra Paosorn ◽  
Sukon Phanichphant

Bismuth vanadate powder was synthesized by a chemical co-precipitation method. Bismuth nitrate and ammonium vanadate were used as the starting precursors. The yellow precipitated powder was formed after adding ammonium hydroxide until the pH of final solution was 7. The powder was filtered and dried at 60 °C for 24h and calcined at 200-400 °C for 2h. The phase of bismuth vanadate powder was studied by X-ray diffraction (XRD). A single phase of monoclinic structure was obtained after calcinations at 200-400 °C for 2h. The morphology and particle size of bismuth vanadate powder were investigated by scanning electron microscopy (SEM). The particle was irregular in shape and highly agglomerated with an average particle size of 0.5 µm in width and 1.5 µm in length.


Author(s):  
Xanthippi Koutsoumbou ◽  
Ioannis Tsiaoussis ◽  
Georgiana Andreea Bulai ◽  
Ovidiu Florin Caltun ◽  
Orestis Kalogirou ◽  
...  

Cobalt ferrite nanoparticles (NPs) doped with rare earth (RE) metals with general formula CoFe2-xRExO4 (RE=Yb, Dy, Gd; x = 0.0 - 0.3) were synthesized by the co-precipitation method followed by post thermal treatment. The influence of RE doping on structural, magnetic and thermal properties and potential biomedical applications like magnetic hyperthermia has been investigated. In the as-prepared samples RE cations enter the spinel lattice as detected by X-ray diffraction. Thermal treatment leads to thermodynamically stable and relaxed single-phase spinel structures only for lower RE content, x = 0.01-0.05. However, annealed samples present higher mass magnetization values (MS), up to 83 Am2/kg. RE content also affects MS, especially in the case of annealed samples where it decreases linearly with x from about 80 Am2/kg (x = 0.01) to about 60 Am2/kg (x = 0.30). Thermal treatment induces a reduction in coercivity from 60-100 mT for as-prepared samples to 18-33 mT for annealed samples, in a nonlinear manner with respect to RE content. Heating efficiency, i.e., Specific Loss Power (SLP), of all samples has been studied using both magnetometric and calorimetric method to deeper examine the energy loss mechanisms involved.


MRS Advances ◽  
2017 ◽  
Vol 2 (64) ◽  
pp. 4025-4030 ◽  
Author(s):  
T. Kryshtab ◽  
H. A. Calderon ◽  
A. Kryvko

ABSTRACTThe microstructure of Ni-Mg-Al mixed oxides obtained by thermal decomposition of hydrotalcite-like compounds synthesized by a co-precipitation method has been studied by using X-ray diffraction (XRD) and atomic resolution transmission electron microscopy (TEM). XRD patterns revealed the formation of NixMg1-xO (x=0÷1), α-Al2O3 and traces of MgAl2O4 and NiAl2O4 phases. The peaks profile analysis indicated a small grain size, microdeformations and partial overlapping of peaks due to phases with different, but similar interplanar spacings. The microdeformations point out the presence of dislocations and the peaks shift associated with the presence of excess vacancies. The use of atomic resolution TEM made it possible to identify the phases, directly observe dislocations and demonstrate the vacancies excess. Atomic resolution TEM is achieved by applying an Exit Wave Reconstruction procedure with 40 low dose images taken at different defocus. The current results suggest that vacancies of metals are predominant in MgO (NiO) crystals and that vacancies of Oxygen are predominant in Al2O3 crystals.


2014 ◽  
Vol 70 (6) ◽  
pp. 1004-1010 ◽  
Author(s):  
Th. I. Shalaby ◽  
N. M. Fikrt ◽  
M. M. Mohamed ◽  
M. F. El Kady

This study investigated the applicability of magnetite Fe3O4 nanoparticles coated with chitosan (CMNs) for the removal of some toxic heavy metals from simulated wastewater. Magnetic nanomaterials were synthesized using the co-precipitation method and characterized by transmission electron microscope, scanning electron microscope, X-ray diffraction, and Fourier transformer infrared spectroscopy. The magnetic properties of the prepared magnetic nanoparticles were determined by a vibrating-sample magnetometer. Batch experiments were carried out to determine the adsorption kinetics of Cr(VI) and Cd(II) by magnetic nanoparticles. It is noteworthy that CMNs show a highly efficient adsorption capacity for low concentration Cr(VI) and Cd(II) ions solution, which can reach 98% within 10 min.


2012 ◽  
Vol 581-582 ◽  
pp. 525-528
Author(s):  
Jia Feng Zhang ◽  
Bao Zhang ◽  
Xue Yi Guo ◽  
He Zhang Chen ◽  
Jian Long Wang ◽  
...  

The LiFe0.98Mn0.02PO4/C was synthesized by spray-drying and low temperature reduction route using FePO4•2H2O as precursor, which was prepared by a simple co-precipitation method. The LiFe0.98Mn0.02PO4/C sample was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and electrochemical measurements. The XRD analysis and SEM images show that sample has the good ordered structure and spherical particle. The charge-discharge tests demonstrate that the powder has the better electrochemical properties, with an initial discharge capacity of 162.1 mAh•g−1 and 155.8 mAh•g−1 at current density of 0.1 C and 1C, respectively. The capacity retention reaches 99.4% after 100 cycles at 1C.


2009 ◽  
Vol 23 (03) ◽  
pp. 365-374 ◽  
Author(s):  
P. MATHUR ◽  
A. THAKUR ◽  
M. SINGH

Mn 0.4 Cu 0.4 Zn 0.2 Fe ferrite was synthesized by soft chemical approach called co-precipitation technique. The ferrite powder was calcined, compacted and sintered at 700°C and 800°C for 3 h. The initial permeability, density, grain size, Curie temperature and dc resistivity have been studied. X-ray diffraction (XRD) method confirmed the sample to be a single-phase spinel structure without unreacted constituents. The particle size was calculated from XRD spectrum using Scherrer's formula and found to be ~55 nm. Then, nanoparticles were observed with tunneling electron microscopy (TEM). Further, scanning electron micrograph (SEM) also confirmed nano-phase and the uniformity of the particles. The initial permeability values do not exhibit much variation with temperature, except near Curie temperature, where it falls sharply. The initial permeability is found to increase with the increase in sintering temperature. This is attributed to the increase in the grain size. Calculation of activation energy indicates that the given ferrite is p-type semiconductor. Mössbauer study of these samples shows superparamagnetic behavior, which also confirms the formation of nano-particles. Possible models and mechanisms contributing to these processes have been discussed.


2015 ◽  
Vol 659 ◽  
pp. 604-608 ◽  
Author(s):  
Jiruntanin Kanoksinwuttipong ◽  
Wisanu Pecharapa ◽  
Russameeruk Noonuruk ◽  
Wicharn Techitdheera

Indium oxide:tin nanoparticles were synthesized by co-precipitation method using InCl3 and SnCl4·5H2O as starting precursor with different molar ratios of Sn:In. The crystalline structure, optical properties, chemical bonding and morphologies of all samples were characterized by X-ray diffraction (XRD), UV–vis spectrometer, Raman spectroscopy and field emission scanning electron microscope, respectively. The XRD results show that the crystallinity of as-synthesized powders was initially amorphous phase. After calcination at 400 °C for 2 h, a single phase ITO powder with 10% (mol%) SnO2 was obtained. The particle size of each sample is approximately 20-25 nm. The color of indium oxide:tin nanopowders after heat treatment changed from white to yellow due to the substitution of oxygen vacancies in the sample. After calcination, the intensity of Raman peak significantly decreased with increasing amount of Sn loading. This phenomenon indicates that ion substitution may occur during the synthesis process. Moreover, it is noticed that the optical absorbance of obviously changed with increasing Sn loading.


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