Structural and Magnetic Properties of Cr- and Fe-Doped CeO2 Nanoparticles Prepared by Sol-Gel Method

2016 ◽  
Vol 848 ◽  
pp. 682-687 ◽  
Author(s):  
Sheng Hong Yang ◽  
Yue Li Zhang
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Measurements ◽  
Physical Property Measurement System ◽  
Sol Gel ◽  
Physical Property ◽  
Ferromagnetic Behavior ◽  
Sem Images ◽  
Uniform Size ◽  
Structural And Magnetic Properties

A study of the structural and magnetic properties of Cr-and Fe-doped CeO2 nanoparticles produced by the sol–gel-based method was undertaken. The crystal structure and phase, morphology, and magnetic properties of the sample were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy (Raman) and physical property measurement system (PPMS). XRD and Raman studied showed that Cr-and Fe-doped did not change CeO2 original cubic fluorite crystal structure, and no ferromagnetic secondary phase was observed. SEM images showed that Cr-and Fe-doped CeO2 nanoparticles were spherical, uniform size, and good dispersion. The particle size was about 20 nm. The magnetic measurements showed that the Cr-and Fe-doped CeO2 nanoparticles presented ferromagnetic behavior at 10 and 300 K, indicating the Curie temperature was above room temperature. The magnetization diminished with the increase of the temperature. The saturation magnetization and coercivity of Fe-doped CeO2 nanoparticles were higher than that of Cr-doped CeO2 nanoparticles. Combined with the results of XRD and Raman, the ferromagnetic behavior can be attributed to the intrinsic properties of Cr-and Fe-doped CeO2 nanostructures.

scholarly journals Structural and Magnetic Properties of Mn Doped BiFeO3 Nanomaterials

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
V. Srinivas ◽  
A. T. Raghavender ◽  
K. Vijaya Kumar
Keyword(s):  
Magnetic Properties ◽  
Doping Concentration ◽  
Structural Changes ◽  
Sol Gel ◽  
Rietveld Analysis ◽  
Ferromagnetic Behavior ◽  
Structural Formation ◽  
Mn Doping ◽  
Structural And Magnetic Properties ◽  
Mn Doped

Nanocrystalline Bi1-xMnxFeO3  (0≤x≤0.3) materials were synthesized using sol-gel technique. The structural and magnetic properties were investigated in detail. Rietveld analysis from XRD revealed the structural formation of BiFeO3. As the Mn doping concentration was increased, the structure of BiFeO3 changed from rhombohedral to tetragonal. All the M-H loops showed the ferromagnetic behavior in the prepared samples. Magnetization was observed to enhance as the Mn doping concentration was increased. The enhanced magnetization may be due to the collapse of the space modulated spin structure as observed from the structural changes.

scholarly journals Optical and Magnetic Properties of Fe Doped ZnO Nanoparticles Obtained by Hydrothermal Synthesis

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Xiaojuan Wu ◽  
Zhiqiang Wei ◽  
Lingling Zhang ◽  
Xuan Wang ◽  
Hua Yang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Diluted Magnetic Semiconductors ◽  
Magnetic Measurements ◽  
Magnetic Semiconductors ◽  
Energy Dispersive Spectrometer ◽  
Blue Shift ◽  
Ferromagnetic Behavior ◽  
Optical And Magnetic Properties ◽  
Doped Zno

Diluted magnetic semiconductorsZn1-xFexOnanoparticles with different doping concentration (x=0, 0.01, 0.05, 0.10, and 0.20) were successfully synthesized by hydrothermal method. The crystal structure, morphology, and optical and magnetic properties of the samples were characterized by X-ray diffraction (XRD), energy dispersive spectrometer (EDS), high-resolution transmission electron microscopy (HRTEM), Raman scattering spectra (Raman), photoluminescence spectra (PL), and the vibrating sample magnetometer (VSM). The experiment results show that all samples synthesized by this method possess hexagonal wurtzite crystal structure with good crystallization, no other impurity phases are observed, and the morphology of the sample shows the presence of ellipsoidal nanoparticles. All theFe3+successfully substituted for the lattice site ofZn2+and generates single-phaseZn1-xFexO. Raman spectra shows that the peak shifts to higher frequency. PL spectra exhibit a slight blue shift and the UV emission is annihilated with the increase ofFe3+concentration. Magnetic measurements indicated that Fe-doped ZnO samples exhibit ferromagnetic behavior at room temperature and the saturation magnetization is enhanced with the increase of iron doping content.

Structural and magnetic properties of pure and cobalt doped Gallium Nitride nanocrystals

2010 ◽  
Vol 1257 ◽  
Author(s):  
Vottikondala Ganesh ◽  
Suresh Sundaram ◽  
Krishnan Baskar
Keyword(s):  
Magnetic Properties ◽  
Gallium Nitride ◽  
Magnetic Measurements ◽  
Raw Materials ◽  
Ferromagnetic Behavior ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
Co Doped

AbstractIn the present study pure and doped gallium nitride (GaN) nanocrystals were synthesized using gallium trichloride (GaCl3), ethylene diamine tetra acetic acid (EDTA) and cobalt chloride as raw materials at a temperature of 900 °C in ammonia (NH3) atmosphere. The XRD spectrum for pure and cobalt doped GaN nanocrystals shows the formation of single phase wurtzite structure. No impurity phases were observed in the X-ray diffraction pattern for 5% Co doped sample whereas secondary phases were observed when the doping concentration exceeds 5 %. Shift in X-ray diffraction peaks were observed in Co doped samples towards lower angle side compared to pure GaN, it confirms that the Co atoms introduces in to the GaN lattice. Transmission electron microscopy images were taken for pure and Co doped GaN. Hexagonal morphology was observed in pure GaN samples. The average size of the particle was found to be ˜20 nm for pure and Co doped GaN. The magnetic measurements were carried out for the Co (5% & 10%) doped samples both at 10K and 300K. Clear hysteresis loop in the magnetization curve suggest the presence of ferromagnetic behavior in cobalt doped GaN. Temperature dependent magnetization (M-T) measurements were also carried out for doped samples using Super Conducting Quantum Interface Device (SQUID) from 10K to 300K The results have been discussed and correlated to structural and magnetic properties of the materials.

scholarly journals Structural and Magnetic Properties of Microwave Assisted Sol-Gel Synthesized La0.9Sr0.1MnO3 Manganite Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Mahin Eshraghi ◽  
Parviz Kameli
Keyword(s):  
Magnetic Properties ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Hysteretic Behavior ◽  
Rhombohedral Structure ◽  
Susceptibility Data ◽  
Slowing Down ◽  
Transmission Electron ◽  
Manganite Nanoparticles ◽  
Structural And Magnetic Properties

The structural and magnetic properties of nanoparticles of La0.9Sr0.1MnO3 (LSMO) were studied using powder X-ray diffraction (XRD), transmission electron microscope (TEM), and magnetic measurements. The XRD refinement result indicates that samples crystallize in the rhombohedral structure with R-3C space group. The dc magnetization measurements revealed that samples exhibit no hysteretic behavior at room temperature, symptomatic of the superparamagnetic (SPM) behavior. The results of ac magnetic susceptibility measurements show that the susceptibility data are not in accordance with the Néel-Brown model for SPM relaxation but fit well with conventional critical slowing down model which indicates that the dipole-dipole interactions are strong enough to cause superspin-glass-like phase in LSMO samples.

scholarly journals The Structural and Magnetic Properties of the Double Rearth Elements La1−xNdxFeO3 Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Nguyen Thi Thuy ◽  
Bach Thanh Cong ◽  
Dang Le Minh
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Magnetic Property ◽  
Room Temperature ◽  
Sol Gel ◽  
Ferromagnetic Behavior ◽  
Orthorhombic Structure ◽  
Nanosized Powders ◽  
Structural And Magnetic Properties ◽  
20 Nm

The double rearth elements La1−xNdxFeO3 (0≤x≤0.5) nanosized powders with orthorhombic structure were prepared by sol-gel method. The particle size of the La1−xNdxFeO3 powder is about 20 nm. The doping of the second rearth element in the A position of the compound ABO3 influenced the crystalline structure and magnetic property of the samples. The M(H) dependence shows that the nanosized La1−xNdxFeO3 samples exhibit ferromagnetic behavior in the room temperature and the M(H) curves are well fitted by Langevin functions.

Structure and Magnetic Properties of (Al, Co) Co-Doped ZnO Thin Films

2012 ◽  
Vol 531-532 ◽  
pp. 299-302
Author(s):  
Ping Cao ◽  
Yue Bai
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Al Doping ◽  
X Ray ◽  
Free Carriers ◽  
Structural And Magnetic Properties ◽  
Co Doped ◽  
Main Factor

In this study, Zn0.99Co0.01Al0.015O thin film has been prepared by sol-gel method. The structural and magnetic properties of the sample were investigated. X-ray diffraction spectroscopy analyses indicate that the Co and Al codoping can not disturb the structure of ZnO. No additional peaks are observed in the Zn0.99Co0.01AlxO and Al3+ and Co2+ substitute for Zn2+ without changing the wurtzite structure. The resistance measurements confirm that Al ions increase the free carriers concentration. Based on the above experiments we think the ferromagnetic behavior of the sample could not originate from Co nanoclusters. The presence of free carriers and localized d spins is a prerequisite for the appearance of ferromagnetism. As the result, the carriers generated by Al doping is considered a main factor to induce the ferromagnetic phenomenon.

Superparamagnetic Magnetite Nanotubes Synthesized by Template-Assisted Sol–Gel Autocombustion

2020 ◽  
Vol 15 (11) ◽  
pp. 1381-1384
Author(s):  
Xinwei Zhang ◽  
Xuanyu Song ◽  
Huiyi Dong ◽  
Chao Zhang ◽  
Chunlei Wang
Keyword(s):  
Magnetic Measurements ◽  
Low Cost ◽  
Physical Property Measurement System ◽  
Sol Gel ◽  
Physical Property ◽  
Average Diameter ◽  
Blocking Temperature ◽  
Synthetic Process ◽  
Aspect Ratios ◽  
Potential Applications

Magnetite nanotubes with an average diameter of about 140 nm were synthesized by an AAO templateassisted sol–gel autocombustion method. The entire synthetic process is convenient, low-cost and nontoxic. The crystalline structure of the magnetite nanotubes was investigated by X-ray diffraction. From the diffraction pattern, we conclude that pure phase magnetite nanotubes were obtained. Tubular morphologies of the products were observed by transmission electron microscope. The as-prepared magnetite nanotubes have a high aspect ratios. The magnetic properties of the nanotubes were measured by a Physical Property Measurement System. The magnetic measurements indicate that the nanotubes have superparamagnetic characteristic at room temperature, and have ferromagnetic characteristic with a coercivity of about 518 Oe at 5 K. The blocking temperature TB of the nanotubes are measured to be 95 K. The as-prepared magnetite nanotubes may find potential applications in bio-medicine.

INFLUENCE OF Fe/Si THICKNESS RATIO ON STRUCTURAL AND MAGNETIC PROPERTIES OF Fe3Si FILMS FABRICATED BY SPUTTERING

2019 ◽  
Vol 26 (01) ◽  
pp. 1850131
Author(s):  
JING XIE ◽  
QUAN XIE ◽  
RUI MA ◽  
JIN HUANG ◽  
CHONG ZHANG
Keyword(s):  
Magnetic Properties ◽  
Magnetic Domain ◽  
Thickness Ratio ◽  
Structural Quality ◽  
Ferromagnetic Behavior ◽  
Sem Images ◽  
Si Substrates ◽  
Film Layer ◽  
Structural And Magnetic Properties ◽  
Si Films

The structural and magnetic properties of Fe3Si films fabricated by layered sputtering on Si substrates dependent on the Fe/Si thickness ratio varying from 2:1 to 4:1 were investigated. X-ray diffraction (XRD) results show that over the whole range of the Fe/Si thickness ratio considered, all films consist of the polycrystalline Fe3Si phase. The film produced with the Fe/Si thickness ratio of 3:1 shows relatively high structural quality. Scanning electron microscopy (SEM) images reveal that the film layer can be clearly observed and the thickness of the film layer at Fe/Si thickness ratio of 3:1 is the thinnest. From the analysis of the magnetization curves, all of these films exhibit ferromagnetic behavior at room temperature. The sample at Fe/Si thickness ratio of 3:1 shows a high [Formula: see text] value of [Formula: see text]831[Formula: see text]emu/cm3, which is slightly lower than the bulk value of Fe3Si. The variety of its coercive force [Formula: see text] is associated with the change of grain size [Formula: see text] through [Formula: see text], and the discrepancy between the [Formula: see text] values of these films and the bulk Fe3Si is due to defects pinning magnetic domain. Meanwhile, the electrical resistivity remarkably decreases with the increase of the Fe/Si thickness ratio.

scholarly journals Structural and magnetic properties of La0.7Sr0.3MnO3 ferromagnetic thin film grown on PMN-PT by sol–gel method

2017 ◽  
Vol 07 (04) ◽  
pp. 1750029 ◽  
Author(s):  
Jing Zhang ◽  
Peng Shi ◽  
Mingmin Zhu ◽  
Ming Liu ◽  
Wei Ren ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetic Properties ◽  
Physical Property Measurement System ◽  
Sol Gel ◽  
Physical Property ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Lower Temperature

We report the preparation of epitaxial La[Formula: see text]Sr[Formula: see text]MnO3 thin films grown on (001)-oriented 0.72Pb(Mg[Formula: see text]Nb[Formula: see text]O3-0.28PbTiO3 substrates by the sol–gel technique. The phase structure, magnetic properties and magnetoresistance of the samples are investigated by using high solution X-ray diffraction, atomic force microscopy, physical property measurement system, respectively. The La[Formula: see text]Sr[Formula: see text]MnO3 thin films display a well-defined hysteresis loop and typical ferromagnetism behavior at lower temperature. High magnetoresistance at 5[Formula: see text]T of 42% appears at 227[Formula: see text]K for La[Formula: see text]Sr[Formula: see text]MnO3 thin film.

scholarly journals Influence of Fe-Doping on the Structural and Magnetic Properties of ZnO Nanopowders, Produced by the Method of Pulsed Electron Beam Evaporation

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
V. G. Il’ves ◽  
S. Yu. Sokovnin ◽  
A. M. Murzakaev
Keyword(s):  
Magnetic Properties ◽  
Electron Beam ◽  
Magnetic Measurements ◽  
Electron Beam Evaporation ◽  
Ferromagnetic Behavior ◽  
Secondary Phases ◽  
Defective Structure ◽  
Pulsed Electron Beam ◽  
Scanning Transmission ◽  
Structural And Magnetic Properties

The nanopowders (NPs) ZnO-Zn-Fe and ZnO-Fe with the various concentrations of Fe (xFe) (0≤xFe≤0.619mass.%) were prepared by the pulsed electron beam evaporation method. The influence of doping Fe on structural and magnetic properties of NPs was investigated. X-ray diffraction showed that powders contain fine-crystalline and coarse-crystalline ZnO fractions with wurtzite structure and an amorphous component. Secondary phases were not found. The magnetic measurements made at room temperature, using the vibration magnetometer and Faraday’s scales, showed ferromagnetic behavior for all powders. Magnetization growth of NPs ZnO-Zn and ZnO-Zn-Fe was detected after their short-term annealing on air at temperatures of 300–500°C. The growth of magnetization is connected with the increase in the concentration of the phase ZnO with a defective structure as the result of oxidation nanoparticles (NPles) of Zn. The scanning transmission electron microscopy (STEM) showed a lack of Fe clusters and uniform distribution of atoms dopant in the initial powder ZnO-Zn-Fe. A lack of logical correlation between magnetization and concentration of a magnetic dopant of Fe in powders is shown.

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