Structural, Electrical and Magnetic Properties of Ni Doped Co-Zn Nanoferrites and their Application in Photo-Catalytic Degradation of Methyl Orange Dye

2015 ◽  
Vol 232 ◽  
pp. 197-211 ◽  
Author(s):  
Santosh Bhukal ◽  
Sandeep Bansal ◽  
Sonal Singhal

Nickel substituted cobalt zinc nanoferrites (Co0.6Zn0.4NixFe2-xO4, x=0.2, 0.4, 0.6, 0.8 and 1.0) were successfully synthesised by sol gel method. FT-IR studies showed two absorption bands in the range of 400-600 cm-1corresponding to the M-O bond in the tetrahedral and octahedral clusters, respectively. Powder X-ray diffraction patterns revealed that all the samples had cubic structure with Fd-3m space group.The lattice constant was observed to increase with increase in nickel substitution, thus altering the unit cell volume. An examination of the magnetic properties revealed an increase in saturation magnetization with increasing Ni concentration upto x=0.4, and a decrease there after.These results could be explained using Neel's collinear two-sub-lattice model and three sub-lattice non-collinear model suggested by Yafet and Kittel. DC resistivity was found to decrease with increase in temperature due to semiconductor nature of nanoferrites. The catalytic activity was found to be maximum at x = 0.2 and further found to decrease with increase in nickel concentration

2018 ◽  
Vol 18 (3) ◽  
pp. 460-469
Author(s):  
Shaima'a J Kareem

In this paper, studying synthesis zinc oxide nanoparticles (ZnO NPs) via sol - gel methodand effect of adding polymer in preparation its solution. Zinc nitrate hexahydrate,Polyvinylpyrrolidone PVP, distilled water and sodium hydroxide (NaOH) were used asprecursor materials. Crystallization behavior of the ZnO was studied by X-ray diffraction(XRD). Nanoparticles phases can change from amorphous to wurtzite structure at thecalcination temperature (500 °C) and crystallite size by Scherrer’s formula about (21.131)nm for samples prepared with distilled water and (20.035)nm for samples prepared withdissolved PVP. Morphological and structural properties were investigated by scanningelectron microscopy (SEM). FT-IR spectra was indicated characteristic absorption bands ofZnO. UV-Vis absorption spectrum was shown a typical spectrum for ZnO nanoparticles.Finally, the results were shown the samples with dissolved PVP has smaller particles size,less agglomeration and narrow distribution but less purity phase when compared withsamples prepared with distilled water.


2021 ◽  
Author(s):  
Harish Kumar ◽  
Ram Mehar Singh ◽  
Ram Pal

Abstract Doping of nanocomposites (NCs) with different metal oxide leads to a significant change in its structural, optical, electrical, mechanical, thermal, catalytic, and magnetic properties. The effect of the addition of CoO nanoparticles (NPs) on the structural, optical, electrical, and magnetic properties of Zn/CoO NCs have been investigated in detail. Zn1-xCoxO NCs were synthesized by the sol-gel method followed by annealing at 4000C. The NCs were characterized by UV-visible, XRD, FTIR, TEM, and vibrating sample magnetometer (VSM) techniques. The structural and surface study was performed by X-ray diffraction and TEM techniques which shows spherical and cubical NCs with an average size of 25-55 nm. Computational study (DMol3, CASTEP, Forcite, and Reflex) was used to study the electronic and optical properties of metal NPs. The Co2+ ions replace Zn2+ ions in the ZnO lattice resulting a change in its structure from Wurtzite (ZnO NPs) to cubic Zn1-xCoxO NCs. The lattice parameters, strain, and dislocation density were found to decrease with an increase in CoO concentration in Zn1-xCoxO NCs. The saturation magnetization, retentivity, and coercivity were found to be lesser in Zn1-xCoxO NCs. The synthesized cobalt doped Zn1-xCoxO NCs can act as an efficient material for spintronic applications.


2012 ◽  
Vol 624 ◽  
pp. 34-37
Author(s):  
Xiao Yan Zhang ◽  
Wen Shu Hu ◽  
Xi Wei Qi ◽  
Gui Fang Sun ◽  
Jian Quan Qi ◽  
...  

Bi2Al4O9 powders were prepared by sol-gel process. The precursors were heated at 500-800°C for 2h to obtain Bi2Al4O9 powder and X-ray diffraction (XRD), Differential thermal analysis (DTA), thermogravimetric analysis (TG), field emission scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) techniques were used to characterize precursor and derived oxide powders. XRD analysis show that the powder is still amorphous after calcined at 500°C. The peaks of Bi2Al4O9 become sharp after calcined at 575°C though still existing some amorphous phase. After calcining at 675-800°C, the powder has fully turned into pure Bi2Al4O9 phase. The crystallization process can also be confirmed by DTA-TG and IR. Calcining the precursor at 575°C, the absorption bands at 527 cm-1, 738 cm-1, 777 cm-1, and 919 cm-1are observed, which are assigned to Bi2Al4O9 and becoming stronger and sharper with the increase of temperature.


2020 ◽  
Vol 32 (3) ◽  
pp. 646-652
Author(s):  
T.R. Smitha ◽  
Thushara Bhadran ◽  
Vaishali Shanker ◽  
K.H. Prema

Nanocomposite materials of nickel ferrite incorporated polyaniline (PANI) have been synthesized via in situ oxidative polymerization technique in a green medium extracted from the fruit of plant Tamarindus indica. Synthesized particles were characterized by FT-IR spectroscopy, X-ray diffraction technique and scanning electron microscopy. Various samples of composites were prepared with 5, 10 and 15 g of filler nickel ferrite and the variation in dielectric permittivity is calculated by measuring the capacitance of the materials in various external frequency ranges from 100 Hz to 20 MHz. Experimental values of dielectric property are compared with theoretical values obtained from Maxwell-Wagner equation. The magnetic properties such as saturation magnetization (Ms), magnetic remanance (Mr) and coercivity (Hc) of the samples were analyzed by vibrating sample magnetometer (VSM). Retention of the magnetic filler in the PANI matrix is evaluated by comparing the experimental Ms values of the composites with the values computed from a theoretical linear equation. The experimental results were well fitted with the theoretical values and confirmed the synthesis of PANI-nickel ferrite composites with desired electrical and magnetic properties by varying the amount of components.


2021 ◽  
Author(s):  
Jiali Song ◽  
Zhi Wang ◽  
Yu Gao

Abstract Nanocrystalline Li 0.35 Ni 0.3 Fe 2.35 O 4 ferrites were prepared at different annealing temperature by sol-gel auto-combustion method. The effects of the annealing temperature on the structure and magnetic properties of the synthesized Li-Ni ferrites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectra (FT-IR) and Squid-VSM. Rietveld refinement of the X-ray diffraction data confirmed the occurrence of phase transition from α-spinel to β-spinel, from which the ideal cation occupation and lattice parameter can be obtained. The grain size increased significantly with annealing temperature. The variation of saturation magnetization can be well explained in terms of the occupation of ions in tetrahedron and octahedron. The coercivity initially increased and later decreased significantly from 115 to 37 Oe with the increase of annealed temperature which could be attributed the fact that the 600℃-annealed grain size is close to transition size from single to multidomain region.


2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.


2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.


2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi

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.


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