scholarly journals Magnetic Characterizations of Sol-Gel-Produced Mn-Doped ZnO

2010 ◽  
Vol 2010 ◽  
pp. 1-3 ◽  
Author(s):  
R. Asmatulu ◽  
H. Haynes ◽  
M. Shinde ◽  
Y. H. Lin ◽  
Y. Y. Chen ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Parent Compound ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Transmission Microscopy ◽  
Resolution Electron ◽  
Ferromagnetic Character ◽  
Electron Transmission Microscopy

Nanoparticles of ZnO doped with 6 at.% Mn were produced by a sol-gel method. X-ray diffraction confirms the hexagonal structure as that of the parent compound ZnO, and high-resolution electron transmission microscopy reveals a single-crystallite lattice. Magnetic measurements using a superconducting quantum interference device indicate that about one half of the Mn2+ions follow Curie's law for paramagnetism. The remaining Mn2+ions exhibit a weak ferromagnetic character, which might be induced through canted antiferromagnetic interactions.

scholarly journals The Optical Properties of Crystalline Zn3Nb2O8Nanomaterials Obtained by Hydrothermal Method

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mihaela Birdeanu ◽  
Mirela Vaida ◽  
Eugenia Fagadar-Cosma
Keyword(s):  
Hydrothermal Method ◽  
Isopropyl Alcohol ◽  
Monoclinic Space Group ◽  
Blue Color ◽  
The Novel ◽  
X Ray Diffraction ◽  
Transmission Microscopy ◽  
X Ray ◽  
Resolution Electron ◽  
Electron Transmission Microscopy

The present study is focused on the obtaining of the Zn3Nb2O8nanomaterial using the hydrothermal method and its characterization through different techniques. X-ray diffraction at room temperature revealed that a novel crystalline form of the nanomaterial forms at 1100°C belonging to monoclinic space group C2/c. Field-emission scanning electron microscopy evidenced the columnar morphology of the particle’s agglomeration and the high resolution electron transmission microscopy confirms the measured interplanar distances calculated from the X-ray diffraction experiments. Using the UV-VIS spectrum and Kubelka-Munk equations, the absorbance and the band gap for the Zn3Nb2O8nanomaterial were calculated. PL spectrum reveals a single peak at 465 nm corresponding to the blue color fluorescence. The novel crystalline nanomaterial might find applications in fluorescence covering of technical devices, due to its capacity to preserve blue fluorescence both in acrylic based paint and after embedding in isopropyl alcohol.

scholarly journals Y3+ substituted Sr-hexaferrites: sol-gel synthesis, structural, magnetic and electrical characterization

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 274-281 ◽  
Author(s):  
S. S. Satpute ◽  
S. R. Wadgane ◽  
S. R. Kadam ◽  
D. R. Mane ◽  
R. H. Kadam
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Combustion Method ◽  
Hexagonal Structure ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
Auto Combustion

Abstract Y3+ substituted strontium hexaferrites having chemical composition SrYxFe12-xO19 (x= 0.0, 0.5, 1.0, 1.5) were successfully synthesized by sol-gel auto-combustion method. The structural and morphological studies of prepared samples were investigated by using X-ray diffraction technique, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy. The X-ray diffraction pattern confirmed the single-phase hexagonal structure of yttrium substituted strontium ferrite and the lattice parameters a and c increased with the substitution of Y3+ ions. The crystallite size also varied with x content from 60 to 80 nm. The morphology was studied by FE-SEM, and the grain size of nanoparticles ranged from 44 to 130 nm. The magnetic properties were investigated by using vibrating sample magnetometer. The value of saturation magnetization decreased from 49.60 to 35.40 emu/g. The dielectric constant decreased non-linearly whereas the electrical dc resistivity increased with the yttrium concentration in strontium hexaferrite.

Enhanced Magnetic and DC Electrical Properties of Sm-Doped Bi2Fe4O9 Nanoplates Synthesized by Sol–Gel Method

NANO ◽  
2020 ◽  
Vol 15 (02) ◽  
pp. 2050020 ◽  
Author(s):  
E. M. M. Ibrahim ◽  
G. Farghal ◽  
Mai M. Khalaf ◽  
Hany M. Abd El-Lateef
Keyword(s):  
Magnetic Measurements ◽  
Small Polaron ◽  
Sol Gel ◽  
Electric Transport ◽  
X Ray Diffraction ◽  
Polaron Hopping ◽  
Gel Method ◽  
Sol Gel Method ◽  
High Temperature Measurement ◽  
Ferromagnetic Ordering

In this work, Bi[Formula: see text]SmxFe4O9 ([Formula: see text], 0.02, 0.06, 0.08, 0.1) nanoplates with an average thickness of 62–125[Formula: see text]nm were synthesized using a sol–gel method. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The magnetic measurements show that the nanoplates have weak ferromagnetic ordering. The saturation magnetization of the nanoplates increases as the Sm content increases. The DC electric transport properties were studied by measuring the temperature dependence of the resistivity in the temperature range 300–680[Formula: see text]K. The materials show typical semiconductor features, and the conduction mechanisms are governed by electron and small polaron hopping in the low and high temperature measurement ranges, respectively. The Sm doping results in a significant enhancement in the electrical conductivity of the Bi2Fe4O9 nanoplates.

Structural, optical and other spectral studies of transition metal Ti4+-doped Zn-Cd oxide nanomaterials

2020 ◽  
Vol 34 (06) ◽  
pp. 2050033 ◽  
Author(s):  
Mohd Saleem ◽  
S. Tiwari ◽  
M. Soni ◽  
N. Bajpai ◽  
Ashutosh Mishra
Keyword(s):  
Sol Gel ◽  
Relaxation Times ◽  
Hexagonal Structure ◽  
Spectral Studies ◽  
X Rays ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
Spectroscopy Analysis ◽  
Auto Combustion ◽  
High Dielectric

Titanium ([Formula: see text])-doped nanoparticles of the type [Formula: see text] [[Formula: see text], [Formula: see text]] are reported in this study. The samples were synthesized by citric acid assisted sol–gel auto combustion (SGAC) method. The samples are characterized by X-ray diffraction (XRD), Raman, Field emission scanning electron microscopy (FESEM), Energy dispersive analysis of X-rays (EDAX) and Fourier transform infra-red (FTIR) techniques for structural studies. Further, for optical properties, UV-Vis technique has been used. In addition, samples were studied for dielectric properties. Room-temperature XRD data study reveals the sample formation with wurtzite hexagonal structure exhibiting space group [Formula: see text]mc also confirmed from Rietveld refinement of XRD data. Raman spectra displays characteristic active phonon modes in pristine [Formula: see text] and doped [Formula: see text]. UV-Vis diffused reflectance spectroscopy analysis infer bandgap values of 3.14 and 3.12 eV for [Formula: see text] and [Formula: see text], respectively. The dielectric studies confirmed high dielectric constant for [Formula: see text] compared to pristine [Formula: see text]. A non-Debye character with spread of relaxation times was witnessed from impedance study.

scholarly journals Size Effects on Magnetic Properties ofNi0.5Zn0.5Fe2O4Prepared by Sol-Gel Method

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Min Zhang ◽  
Zhenfa Zi ◽  
Qiangchun Liu ◽  
Peng Zhang ◽  
Xianwu Tang ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Domain Wall Motion ◽  
Blocking Temperature ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Cation Redistribution

Ni0.5Zn0.5Fe2O4particles with different particle sizes have been synthesized by sol-gel method. X-ray diffraction results show that all the samples are pure cubic spinel structure with their sizes ranging from 9 to 96 nm. The lattice constant significantly decreases with further increasing annealing temperature. The magnetic measurements show superparamagnetic nature below the particle size of 30 nm, while others show ferrimagnetic nature above the corresponding blocking temperature. The blocking temperature increases with the increase in particle size, which can be explained by Stoner-Wohlfarth theory. The saturation magnetization increases as the particle size increases, which can be explained by the cation redistribution on tetrahedral A and octahedral B sites and the domain wall motion. The variation of coercivity as a function of particle size is based on the domain structure.

Synthesis of Co@Au Core-Shell Nanoparticles in Non-Aqueous Solution and their Characterization

2004 ◽  
Vol 818 ◽  
Author(s):  
Zhihui Ban ◽  
C. J. O'Connor
Keyword(s):  
Aqueous Solution ◽  
Quantum Interference ◽  
Au Nanoparticles ◽  
Magnetic Measurements ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
Transmission Electron ◽  
Average Size ◽  
Core Shell Nanoparticles

AbstractA homogeneous non-aqueous solution reactions method has been developed to prepare gold-coated cobalt (Co@Au) nanoparticles. After the sample was washed with 8% HCl, XRD (X-Ray Diffraction), TEM (transmission electron microscopy), and magnetic measurements SQUID (Superconducting Quantum Interference Device) are utilized to characterize the nanocomposites. XRD shows the pattern of sample, which is responding to gold and cobalt, no cobalt oxide was found. TEM results show that the average size of Co@Au nanoparticles is about 10 nm and we can find core-shell structure of the sample. SQUID results show that the particles are ferromagnetic materials at 300K. So the gold- coated cobalt nanoparticles (Co@Au) can be successfully prepared by the homogeneous nonaqueous approach. This kind of core-shell materials is stable in acid condition, which would give many opportunities for bio- application.

Structural, Magnetic, and Electrical Properties of BiFe1-xMnxO3 Thin Films

2009 ◽  
Vol 1199 ◽  
Author(s):  
Danilo G Barrionuevo ◽  
Surinder P Singh ◽  
Maharaj S. Tomar
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Ion Concentration ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Sol Gel Process

AbstractWe synthesized BiFe1-xMnxO3 (BFMO) for various compositions by sol gel process and thin films were deposited by spin coating on platinum Pt/Ti/SiO2/Si substrates. X-ray diffraction shows all the diffraction planes corresponding to rhombohedrally distorted perovskite BiFeO3 structure. The absence of any impurity phase in the films suggests the incorporation Mn ion preferentially to Fe site in the structure for low concentration. Magnetic measurements reveal the formation of ferromagnetic phase at room temperature with increased Mn substitution. On the other hand, ferroelectric polarization decreases with increasing Mn ion concentration. Raman studies suggest the dopant induced structural distortion.

scholarly journals Phase Pure Synthesis and Morphology Dependent Magnetization in Mn Doped ZnO Nanostructures

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Murtaza Saleem ◽  
Shahid Atiq ◽  
Shahid M. Ramay ◽  
Asif Mahmood ◽  
Saadat A. Siddiqi ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Electron Microscopic ◽  
Structural Morphology ◽  
X Ray ◽  
Phase Pure ◽  
Doped Zno ◽  
Mn Doped

Zn0.95Mn0.05O nanostructures were synthesized using sol gel derived autocombustion technique. As-burnt samples were thermally annealed at different temperatures (400, 600, and 800°C) for 8 hours to investigate their effect on structural morphology and magnetic behavior. X-ray diffraction and scanning electron microscopic studies demonstrated the improvement in crystallinity of phase pure wurtzite structure of Mn doped ZnO with variation of annealing temperature. Energy dispersive X-ray elemental compositional analysis confirmed the exact nominal compositions of the reactants. Electrical resistivity measurements were performed with variation in temperature, which depicted the semiconducting nature similar to parent ZnO after 5 at% Mn doping. Magnetic measurements by superconducting quantum interference device detected an enhanced trend of ferromagnetic interactions in thermally annealed compositions attributed to the improved structural morphology and crystalline refinement process.

scholarly journals The Effects and Role of Polyvinylpyrrolidone on the Size and Phase Composition of Iron Oxide Nanoparticles Prepared by a Modified Sol-Gel Method

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Marcela F. Silva ◽  
Luiz A. S. de Oliveira ◽  
Mariani A. Ciciliati ◽  
Michele K. Lima ◽  
Flávio F. Ivashita ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
Transmission Microscopy ◽  
Gel Method ◽  
Sol Gel Method ◽  
Oxide Phases ◽  
Nuclear Environment

Fe2O3 nanoparticles (as maghemite and hematite mixtures) were prepared using adapted sol-gel method from a polyvinylpyrrolidone (PVP) aqueous solution in various Fe3+ : PVP monomer ratios. Analysis of X-ray diffraction was obtained to evaluate the crystalline state, average crystallite size, and composition of iron oxide phases. The morphology and average nanoparticles size were evaluated by electronic transmission microscopy. Magnetic properties of iron oxide were analyzed at low and room temperatures. Optical characteristics were evaluated by UV-Vis photoacoustic spectroscopy and the Mössbauer spectrum was obtained in order to evaluate subtle changes in the nuclear environment of the iron atoms.

Studies on conducting nanocomposite with gallium nitride–doped ferrite, part – I

2016 ◽  
Vol 231 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Rajani Indrakanti ◽  
V Brahmaji Rao ◽  
C Udaya Kiran
Keyword(s):  
Electron Microscope ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Ferromagnetic State ◽  
Energy Dispersive ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Scherrer Formula

This article presents the synthesis and the structural, morphological, magnetic and spectroscopic characterisations of GaN-doped Fe2O3 nanoparticles prepared by the sol–gel method. The ‘Sci find’ software was unable to trace any of the references to point out the earlier knowledge and existence of this novel compound in the literature. We claim our contribution for the same. The structural analysis is done using the X-ray diffraction and energy-dispersive X-ray analysis, while the morphological analysis is done by the scanning electron microscope and the transmission electron microscope. The samples show a simple cubic crystalline structure. The morphological and energy-dispersive X-ray analysis and the infrared studies confirm the composition of the material and the particle sizes of the samples are found to be in the range of 9–27 nm (for x = 0.5) and 23–30 nm (for x = 0.75). The particle sizes, obtained from the histogram evaluations, the Debye–Scherrer formula in X-ray diffraction and the selected area electron diffraction measurements are all in good agreement. The room temperature magnetic measurements obtained using the vibration sample magnetometer for x = 0.5, 0.75,1 and 5 are presented as the hysteresis curves and their related plots. The discussion about the conclusions drawn therein infers that the coercivity increases with the concentration. The compound exhibits spinel structure and vivid changes from the super paramagnetic to the ferromagnetic state.

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