Comparative Study of Pure and Ni-Doped ZnFe2O4 Nanoparticles for Structural, Optical and Magnetic Properties

2013 ◽  
Vol 699 ◽  
pp. 524-529 ◽  
Author(s):  
A. Manikandan ◽  
J. Judith Vijaya ◽  
L. John Kennedy

Pure and Ni-doped ZnFe2O4 nanoparticles, Zn1-xNixFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) were synthesized by microwave combustion method (MCM). The structural, morphological and magnetic properties of the products were determined by X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM) and vibrating sample magnetometer (VSM). X-ray analysis showed that all the compositions crystallize with cubic spinel structure. The broadband visible emission is observed in the entire photoluminescence (PL) spectrum and the estimated energy band gap is about 2.1 eV. VSM measurements shows superparamagnetic behavior for lower concentration of Ni (x ≤ 0.2), whereas for higher concentration (x ≥ 0.2), it becomes ferromagnetic. The saturation magnetization (Ms) varies considerably with Ni content to reach a maximum value for Ni0.5Zn0.5Fe2O4 composition, i.e. 57.89 emu/g.

2015 ◽  
Vol 29 (14) ◽  
pp. 1550090 ◽  
Author(s):  
O. Mirzaee ◽  
R. Mohamady ◽  
A. Ghasemi ◽  
Y. Alizad Farzin

Nanostructure of Y-type hexaferrite with composition of Sr 2 Ni 2 Al x/2 Cr x/2 Fe 12-x O 22 (where x are 0, 0.6, 1.2, 1.8, 2.4 and 3) were prepared by sol–gel auto-combustion method. The influence of Al and Cr doping on the structural and magnetic properties has been investigated. The X-ray diffraction (XRD) patterns confirm phase formation of Y-type hexaferrite. The microstructure and morphology of prepared samples were studied by high resolution field emission scanning electron microscope (FESEM) which shows the hexagonal shape for all of the samples. Magnetic properties were characterized using vibrating sample magnetometer (VSM). The magnetic results revealed that by increasing the Al and Cr to the structure, the coercivity was also increased from 840 Oe to 1160 Oe. Moreover it has been shown that with addition of dopants, saturation magnetization (Ms) and remnant magnetization (Mr) were decreased from 39.61 emu/g to 30.11 emu/g and from 17.51 emu/g to 14.62 emu/g, respectively, due to the entrance of nonmagnetic ions into Fe 3+ sites.


2018 ◽  
Vol 4 (5) ◽  
pp. 536-538
Author(s):  
Anil S. Jadhav ◽  
B. Raghunanda ◽  
Ashok D. Shetkar ◽  
Ajai Kumar S. Molakeri

Zinc ferrite (ZnFe2O4) nanocrystalline powder material was prepared by combustion method. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) is used to study on structural properties. The magnetic properties of the sample were measured at room temperature using vibrating sample magnetometer (VSM) in the field range �15000 G. Hysteresis loop obtained room temperature for ZnFe2O4 nanoparticles indicates that the nanoparticles are ferromagnetic in nature.


Orthorhombic structured bismuth molybdate (Bi2MoO6) is obtained by one pot microwave combustion method. The characteristic performance of Bi2MoO6 nanocatalyst are described by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) furnished with Energy - dispersive X-ray spectroscopy (EDS) and Fourier change infrared (FT-IR) spectroscopy. The average crystallite size for Bi2MoO6 estimated from XRD is about 28.9 nm. The surface morphology from SEM pictures displays nanoplates. The FTIR is utilized to recognize the structural coordination and the presence of functional group. The electrochemical studies are taken to readily comprehend the electrochemical performance of the modified active electrode with notable specific capacitance value are found 234.9 Fg-1 at 5 mVs-1 and cyclic retention is stable up to 900 cycles (98.7 %). The as-synthesized dynamic material acts as a novel electrode material for supercapacitor.


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.


2015 ◽  
Vol 1101 ◽  
pp. 286-289 ◽  
Author(s):  
Maya Rahmayanti ◽  
Sri Juari Santosa ◽  
Sutarno

Gallic acid-modified magnetites were synthesized by one and two-step reactions via the newly developed sonochemical co-precipitation method. The two-step reaction included the formation of magnetite powder and mixing the magnetite powder with gallic acid solution, while the one-step reaction did not go through the formation magnetite powder. The obtained gallic acid-modified magnetites were characterized by the Fourier Transform Infrared (FTIR) spectroscopy, the X-Ray Diffraction (XRD) and the Scanning Electron Microscopy (SEM). More over, the magnetic properties were studied by using a Vibrating Sample Magnetometer (VSM). The characterization results showed that there were differences in crystalinity, surface morphology and magnetic properties of products that were formed by one and two-step reactions.


2010 ◽  
Vol 177 ◽  
pp. 32-36 ◽  
Author(s):  
An Rong Wang ◽  
Jian Li ◽  
Qing Mei Zhang ◽  
Hua Miao

Weak magnetic ZnFe2O4 nanoparticles were prepared by coprecipitation and treated with different concentrations of Fe(NO3)3 solution. Untreated and treated particles were studied using a vibrating sample magnetometer, transmission electron microscope, by X-ray diffraction, X-ray energy dispersive spectroscopy and X photoelectron spectroscopy. The results showed that, after treatment, the ZnFe2O4/γ-Fe2O3 forms disphase nanoparticles, with enlarged size, enhanced magnetic properties and with a surface parceled with Fe(NO3)3. The size of the particles and their magnetic properties are related to the concentration of the treatment solution. The particle size and magnetic properties could be controlled by controlling the concentration of treating solution, therefore nanoparticles can be more widely used.


2011 ◽  
Vol 295-297 ◽  
pp. 551-554 ◽  
Author(s):  
Jia Yue Sun ◽  
Chun Cao ◽  
Hai Yan Du

Erbium and ytterbium co-doped sodium yttrium fluoride (NaYF4:Er3+,Yb3+) was synthesized by combusting in home microwave oven directly. The structure and morphology of the sample was characterized by the X-ray diffraction (XRD) and scanning electron microscopy (SEM), and its upconversion luminescence properties were investigated in detail. Under 980nm semiconductor laser excitation, the color of upconversion luminescence of NaYF4:Er3+,Yb3+ was green and red, and its upconversion spectrum exhibited distinct emission peaks at 522, 543 and 652 nm, the emission appears yellow-orange to the naked eye. The law of luminescence intensity versus pump power proved that the intense green emission at 522 and 543 nm were from Er3+(2H11/2→4I15/2and4S3/2→4I15/2), and the weaker red emission at 652 nm was from Er3+(4F9/2→4I15/2), which belong to the two photon process.


2002 ◽  
Vol 753 ◽  
Author(s):  
I. Baker ◽  
R. G. Quiller ◽  
M. Robson ◽  
D. Wu

ABSTRACTPowders of near-equiatomic Fe and Co were mechanically milled with additions of Zr, C, Ni, Cu and/or B for 60 hr using stainless steel balls in a Svegari attritor operated at 1300 r.p.m. under argon. The milled powders were examined before and after annealing at 600 °C. The morphologies and sizes of the powders were examined using a scanning electron microscope. The grain sizes were characterized from the widths of X-ray diffraction peaks obtained using a computer-controlled x-ray diffractometer and the lattice parameters were determined. The resulting magnetic properties were measured using a vibrating sample magnetometer.


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