Synthesis and Characterization of Superparamagnetic NiFe2O4 Nanoparticles

2010 ◽  
Vol 663-665 ◽  
pp. 1325-1328 ◽  
Author(s):  
De Hui Sun ◽  
De Xin Sun ◽  
Yu Hao
Keyword(s):  
Room Temperature ◽  
Size Range ◽  
X Ray Diffraction ◽  
Inverse Spinel ◽  
Cubic Crystal ◽  
Xrd Pattern ◽  
X Ray ◽  
Nife2o4 Nanoparticles ◽  
Average Size

The superparamagnetic NiFe2O4 nanoparticles were synthesized using a hydrothermal technology through P123 sphere micelles as ‘nanoreactor’ in this work. Their morphologies, structures, surface properties and magnetism were characterized by FE-SEM, XRD, FTIR, and VSM, respectively. The nickel ferrite samples are nearly spherical and homogeneous nanoparticles with average size range of about 50-120 nm. They possess superparamagnetism at room temperature and higher saturation magnetization. X-ray diffraction (XRD) pattern confirms that the samples belong to the cubic crystal system with an inverse-spinel structure. Fourier transform infrared (FTIR) absorption spectrum indicates that the NiFe2O4 nanoparticles are stabilized by the P123 adsorbed on the surface of nanoparticles.

Synthesis of Monodisperse Fe3O4 Microspheres and Effect of the Precursor Concentration

2011 ◽  
Vol 183-185 ◽  
pp. 2327-2330 ◽  
Author(s):  
De Hui Sun ◽  
De Xin Sun ◽  
Ming Xing Han
Keyword(s):  
Room Temperature ◽  
Size Range ◽  
Precursor Concentration ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Xrd Pattern ◽  
X Ray ◽  
Magnetic Investigation ◽  
Cubic Structure ◽  
Average Size

In present work, we synthesized monodisperse Fe3O4microsphere using a free-surfactant solvothermal reduction route and investigated effect of the precursor concentration (FeCl3∙6H2O and NaAc) on microsphere sizes under other reaction conditions held constant. The morphologies, structures, and magnetism of the products were characterized by SEM, XRD, FTIR and VSM. The results showed that the Fe3O4 microsphere with a tunable average size range from 120 nm to 300 nm is composed of many Fe3O4collective nanoparticles. Their average diameters increased with increase of precursor FeCl3∙6H2O concentration but decreased with increase of precursor NaAc concentration. The X-ray diffraction (XRD) pattern confirmed that the Fe3O4microspheres belong to cubic structure. Magnetic investigation reveals that the Fe3O4microspheres have higher saturation magnetization and negligible coercivity at room temperature.

Synthesis and Characterization of Superparamagnetic Fe3O4 Nanoparticles

2013 ◽  
Vol 750-752 ◽  
pp. 340-343 ◽  
Author(s):  
De Hui Sun ◽  
Jiao Wu ◽  
Ji Lin Zhang
Keyword(s):  
Room Temperature ◽  
Thermal Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Xrd Pattern ◽  
X Ray ◽  
Magnetic Investigation ◽  
Average Size

We synthesized Fe3O4 nanoparticles using a solvent thermal method and characterized the morphologies, structures, surface properties, thermal stability and magnetism of the products by Field emission scanning electron microscopy (FE-SEM), Powder X-ray diffraction (XRD), Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and vibrating sample magnetometer (VSM). The experimental results showed that the Fe3O4 nanoparticles have a tunable average size range from 55 nm to 85 nm. Their diameters decreased with increase of precursor FeCl24H2O concentration or increase of the reaction time under other reaction conditions held constant. The XRD pattern confirmed that the Fe3O4 nanoparticles belong to cubic structure. Magnetic investigation reveals that the Fe3O4 nanoparticles have higher saturation magnetization and negligible coercivity at room temperature.

Synthesis and Characterization of Magnetic NiFe2O4 Nanosheets

2011 ◽  
Vol 239-242 ◽  
pp. 2520-2523 ◽  
Author(s):  
Zhen Feng Cui ◽  
De Hui Sun
Keyword(s):  
Room Temperature ◽  
Solution Method ◽  
Energy Dispersive Spectrum ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Inverse Spinel ◽  
Cubic Crystal ◽  
X Ray ◽  
Composition And Structure

We have synthesized the magnetic NiFe2O4nanosheets using a solution method in the presence of hexamethylenetetramine (HMTA). Morphologies, composition and structure of the as-synthesized samples are characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive spectrum (EDS) and X-ray diffraction (XRD), respectively. Fourier transform infrared (FTIR) spectroscopy and vibrating sample magnetometer (VSM) are used to investigate the surface properties and magnetic properties of the NiFe2O4nanosheets. FE-SEM results show that the NiFe2O4nanosheet samples have irregular shape with thickness of about 30 nm. XRD result confirms that the samples belong to the cubic crystal system with an inverse-spinel structure. The NiFe2O4nanosheets possess sub-ferromagnetism with a negligible coercivity and remanence at room temperature. It could become novel magnetic materials with the potential application in sensors, catalyst, and microwave devices.

Solvothermal Synthesis and Magnetic Properties of Fe3O4 Microspheres

2011 ◽  
Vol 393-395 ◽  
pp. 947-950
Author(s):  
De Hui Sun ◽  
Ji Lin Zhang ◽  
De Xin Sun
Keyword(s):  
Room Temperature ◽  
Size Range ◽  
Solvothermal Method ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Magnetic Investigation ◽  
Xrd Patterns ◽  
Fe3o4 Microspheres ◽  
Ftir Absorption Spectra

We synthesized Fe3O4 microspheres using a solvothermal method and characterized their morphologies, structures, surface property and magnetism by field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD) patterns, Fourier transform infrared (FTIR) absorption spectra, and vibrating sample magnetometer (VSM). The results showed that the synthesized Fe3O4 microspheres with a tunable size range of ca. 80–200 nm are composed of many Fe3O4 collective nanoparticles. XRD pattern confirmed that the Fe3O4 microspheres belong to cubic structure. Magnetic investigation reveals that the Fe3O4 microspheres have higher saturation magnetization and negligible coercivity at room temperature.

Synthesis and Characterization of CoFe2O4 Nanoparticles

2011 ◽  
Vol 261-263 ◽  
pp. 533-536 ◽  
Author(s):  
Zhen Feng Cui ◽  
Dehui Sun
Keyword(s):  
Solution Method ◽  
Size Range ◽  
Information Storage ◽  
Resonance Imaging ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Rhombohedral Crystal ◽  
Average Size

We synthesized the magnetic CoFe2O4nanoparticles using a solution method in the presence of hexamethylenetetramine (HMTA) at 85 °C for 6 h. Their morphologies, structures, surface properties and magnetism were characterized by Field emission scanning electron microscopy (FE-SEM) images, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and Vibrating sample magnetometer (VSM), respectively. FE-SEM results show that the synthesized samples are irregular nanoparticles with average size range of about 40-120 nm. XRD confirms that the samples belong to the rhombohedral crystal system. The magnetic CoFe2O4nanoparticles have the potential application in magnetic resonance imaging, high-density information storage and drug delivery.

Synthesis and Characterization of MFe2O4(M=Co,Ni) Nanoparticles

2011 ◽  
Vol 236-238 ◽  
pp. 1893-1896
Author(s):  
De Hui Sun ◽  
Ji Lin Zhang ◽  
De Xin Sun
Keyword(s):  
Room Temperature ◽  
Synthesis Method ◽  
Rhombohedral Structure ◽  
Ni Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Xrd Patterns ◽  
Average Size ◽  
Ftir Absorption Spectra

The magnetic MFe2O4 (M=Co, Ni) nanoparticles are synthesized using a hydrothermal synthesis method in ethylene glycol (EG) solution. Their morphologies, structures, surface properties and magnetism are characterized by field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD), fourier transform infrared (FTIR) absorption spectra, and vibrating sample magnetometer (VSM), respectively. The nickel ferrite and the cobalt ferrite samples are nearly spherical and homogeneous nanoparticles with average size range of about 90 nm (NiFe2O4) and 30 nm (CoFe2O4). XRD patterns confirm that the NiFe2O4 samples belong to the cubic structure and the CoFe2O4 samples are the rhombohedral structure. The NiFe2O4 nanoparticles are superparamagnetic at room temperature, while the CoFe2O4 nanoparticles are sub-ferromagnetic at room temperature and possess higher saturation magnetization.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

scholarly journals Synthesis and Characterization of Lithium-Ion Conductive LATP-LaPO4 Composites Using La2O3 Nano-Powder

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3502
Author(s):  
Fangzhou Song ◽  
Masayoshi Uematsu ◽  
Takeshi Yabutsuka ◽  
Takeshi Yao ◽  
Shigeomi Takai
Keyword(s):  
Room Temperature ◽  
Conduction Mechanism ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Nano Powder ◽  
Powder Addition

LATP-based composite electrolytes were prepared by sintering the mixtures of LATP precursor and La2O3 nano-powder. Powder X-ray diffraction and scanning electron microscopy suggest that La2O3 can react with LATP during sintering to form fine LaPO4 particles that are dispersed in the LATP matrix. The room temperature conductivity initially increases with La2O3 nano-powder addition showing the maximum of 0.69 mS∙cm−1 at 6 wt.%, above which, conductivity decreases with the introduction of La2O3. The activation energy of conductivity is not largely varied with the La2O3 content, suggesting that the conduction mechanism is essentially preserved despite LaPO4 dispersion. In comparison with the previously reported LATP-LLTO system, although some unidentified impurity slightly reduces the conductivity maximum, the fine dispersion of LaPO4 particles can be achieved in the LATP–La2O3 system.

scholarly journals MOVPE Growth of Quaternary (Al,Ga,In)N for UV Optoelectronics

2000 ◽  
Vol 5 (S1) ◽  
pp. 412-424
Author(s):  
Jung Han ◽  
Jeffrey J. Figiel ◽  
Gary A. Petersen ◽  
Samuel M. Myers ◽  
Mary H. Crawford ◽  
...  
Keyword(s):  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Optoelectronic Devices ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Peak Energy ◽  
Movpe Growth ◽  
Pl Emission

We report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.

scholarly journals Metal-Rich Metallaboranes: Synthesis, Structures and Bonding of Bi- and Trimetallic Open-Faced Cobaltaboranes

Inorganics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 28
Author(s):  
Kriti Pathak ◽  
Chandan Nandi ◽  
Jean-François Halet ◽  
Sundargopal Ghosh
Keyword(s):  
Electronic Structures ◽  
Density Functional ◽  
Room Temperature ◽  
Electron Pair ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Cluster 2 ◽  
Cobalt Center

Synthesis, isolation, and structural characterization of unique metal rich diamagnetic cobaltaborane clusters are reported. They were obtained from reactions of monoborane as well as modified borohydride reagents with cobalt sources. For example, the reaction of [Cp*CoCl]2 with [LiBH4·THF] and subsequent photolysis with excess [BH3·THF] (THF = tetrahydrofuran) at room temperature afforded the 11-vertex tricobaltaborane nido-[(Cp*Co)3B8H10] (1, Cp* = η5-C5Me5). The reaction of Li[BH2S3] with the dicobaltaoctaborane(12) [(Cp*Co)2B6H10] yielded the 10-vertex nido-2,4-[(Cp*Co)2B8H12] cluster (2), extending the library of dicobaltadecaborane(14) analogues. Although cluster 1 adopts a classical 11-vertex-nido-geometry with one cobalt center and four boron atoms forming the open pentagonal face, it disobeys the Polyhedral Skeletal Electron Pair Theory (PSEPT). Compound 2 adopts a perfectly symmetrical 10-vertex-nido framework with a plane of symmetry bisecting the basal boron plane resulting in two {CoB3} units bridged at the base by two boron atoms and possesses the expected electron count. Both compounds were characterized in solution by multinuclear NMR and IR spectroscopies and by mass spectrometry. Single-crystal X-ray diffraction analyses confirmed the structures of the compounds. Additionally, density functional theory (DFT) calculations were performed in order to study and interpret the nature of bonding and electronic structures of these complexes.

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