scholarly journals Preparation and Magnetic Properties of ZnFe2O4Nanotubes

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Yan Xu ◽  
Yantian Liang ◽  
Lijuan Jiang ◽  
Huarui Wu ◽  
Hongzhi Zhao ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Sol Gel ◽  
Anodic Aluminum Oxide Template ◽  
Blocking Temperature ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anodic Aluminum ◽  
Transmission Electron

Ordered ZnFe2O4nanotube arrays with the average outer diameter of 100 nm were prepared in porous anodic aluminum oxide template using an improved sol-gel approach. The morphology was studied by transmission electron and field emission scanning electron microscope. X-ray diffraction result shows that the nanotubes were polycrystalline in structure. The magnetic properties of the prepared ZnFe2O4nanotubes were also studied. The results show that the sample shows typical superparamagnetism at room temperature and obvious ferromagnetism below blocking temperature.

scholarly journals Photo-acoustic properties of nanoTiO2:Er

2016 ◽  
Vol 5 (4) ◽  
pp. 196
Author(s):  
R. Palomino-Merino ◽  
R. Lozada-Morales ◽  
J. Martínez-Juárez ◽  
G. Juárez-Díaz ◽  
J. Carmona-Rodriguez ◽  
...  
Keyword(s):  
Room Temperature ◽  
Sol Gel ◽  
Acoustic Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Average Grain Size ◽  
Electron Dispersion ◽  
Er Doped ◽  
Spectroscopy Optical

Nanocrystalline Er-doped TiO2 was prepared by sol-gel at room temperature. X-ray diffraction, photoacoustic spectroscopy (optical absorption), transmission electron microscopy (TEM), and electron dispersion microscopy (EDS) were carried out on both as-prepared and thermally-annealed (air at 700 ºC) samples, revealing the anatase crystalline phase of TiO2. The samples exhibit an average grain size from 38 to 5.1 nm, as the nominal concentration of Er varies from 0 % to 7 %. The photoacoustic spectra evidence the absorption edge at 300 nm attributed to TiO2, as well as several electronic transitions which are atomic energy absorption-line levels characteristics of Er.

H2 Uptake and Synthesis of the Li-dispersed Manganese Oxide Nanotubes

2007 ◽  
Vol 7 (11) ◽  
pp. 4033-4036 ◽  
Author(s):  
Jin Bae Lee ◽  
Soon Chang Lee ◽  
Hae Jin Kim
Keyword(s):  
Electron Microscopy ◽  
Manganese Oxide ◽  
Hydrogen Adsorption ◽  
Gravimetric Method ◽  
Anodic Aluminum Oxide Template ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
Anodic Aluminum ◽  
Transmission Electron ◽  
Potential Applications

Well aligned Li-dispersed manganese oxide nanotubes were prepared using LiNO3, Mn(NO3)2 · xH2O and an anodic aluminum oxide template by solvent-free method for potential applications in H2 storage. The obtained nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The analyses revealed the Mn2O3 nanotubes to have a cubic structure with a uniform length, 40–50 nm in wall thickness and 250 ± 10 nm in the outer diameter. The level of H2 adsorption was determined using the gravimetric method. The Li-dispersed manganese oxide nanotubes showed a 0.26 wt% for the amount of hydrogen adsorption at 77 K under 4.5 MPa.

scholarly journals Solvothermal Synthesis and Magnetic Properties of Monodisperse Ni0.5Zn0.5Fe2O4 Hollow Nanospheres

2019 ◽  
Vol 38 (2019) ◽  
pp. 76-83 ◽  
Author(s):  
Min Zhang ◽  
Qiangchun Liu
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Solvothermal Method ◽  
Blocking Temperature ◽  
Hollow Nanospheres ◽  
X Ray Diffraction ◽  
Magnetic Studies ◽  
X Ray ◽  
Reactant Concentration ◽  
Structure Surface

AbstractThe monodisperse Ni0.5Zn0.5Fe2O4 nanospheres have been synthesized via a simple solvothermal method. The effects of reactant concentration on structural and magnetic properties have been studied. X-ray diffraction analysis results indicate that the lattice constant and crystallite size can be tuned by controlling reactant concentration. The nanosphere size monotonically decreases from 238 to 35 nm with increasing reactant concentration. The magnetic studies show that blocking temperature is enhanced, and these single-domain particles are superparamagnetism at room temperature. The hollow nanospheres exhibit a high saturation magnetization value of 52.6 emu/g. The nanospheres with various diameters exhibit different magnetic saturation values which may be caused by the domain structure, surface effects and the distribution of metal ions on A and B sites. These superparamagnetic Ni0.5Zn0.5Fe2O4 nanospheres are expected to have potential application in biomedicine and magnetic fluid technology.

scholarly journals Fabrication and magnetic properties of hierarchical nickel microwires with nanothorns

2010 ◽  
Vol 8 (2) ◽  
pp. 434-439 ◽  
Author(s):  
Junhao Zhang ◽  
Ling Yang ◽  
Xiaofang Cheng ◽  
Jinmeng Zhang ◽  
Fucai Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Cooperative Effect ◽  
Magnetic Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

AbstractHierarchical nickel microwires with nanothorns were fabricated through a reduction of nickelous salt with hydrazine in diethanolamine. The product was characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). The growth mechanism of the nickel microwires with nanothorns is proposed, based on the evolution of the structures and morphologies, which could be ascribed to the cooperative effect of the complexant of diethanolamine and inherent magnetic interactions. Magnetic properties of the product were measured at room temperature and compared with other shaped counterparts.

Fabrication of ordered Ta2O5 nanodots using an anodic aluminum oxide template on Si substrate

2007 ◽  
Vol 22 (4) ◽  
pp. 1064-1071 ◽  
Author(s):  
Ching-Jung Yang ◽  
Chih Chen ◽  
Pu-Wei Wu ◽  
Jia-Min Shieh ◽  
Shun-Min Wang ◽  
...  
Keyword(s):  
Aluminum Oxide ◽  
Photoelectron Spectroscopy ◽  
Anodic Aluminum Oxide ◽  
Anodic Aluminum Oxide Template ◽  
X Ray Diffraction ◽  
General Applicability ◽  
X Ray ◽  
Anodic Aluminum ◽  
Transmission Electron ◽  
Anodization Process

Ordered arrays of Ta2O5 nanodots were prepared using anodic aluminum oxide (AAO) as a template to support localized oxidation of TaN. Films of TaN (50 nm) and Al (1.5 μm) were deposited successively on p-type Si wafers and followed by a two-step anodization process at 40 V using oxalic acid as the electrolyte. The first anodization promoted growth of irregular AAO from overlying Al film. After chemical etching, the second anodization was performed to develop well-organized AAO channels and initiate oxidation of underlying TaN film to form tantalum oxide nanodots at the AAO pore bottoms. X-ray photoelectron spectroscopy results confirmed the chemical nature of nanodots as stoichmetric Ta2O5. X-ray diffraction demonstrated the amorphous characteristic of Ta2O5. As shown in field-emission scanning electron microscopy and transmission electron results, the Ta2O5 nanodots exhibited a hillock structure 80 nm in diameter at the bottom and 50 nm in height. We also synthesized 30-nm nanodots by adjusting AAO formation electrochemistry. This demonstrates the general applicability of the AAO template method for nanodot synthesis from nitride to oxide at a desirable size.

Magnetic Properties of Mg0.4Ca0.6Fe2O4 Nanoparticles Synthesized by Sol-Gel Method for Hyperthermia Treatment

2014 ◽  
Vol 631 ◽  
pp. 193-197
Author(s):  
A.M. Escamilla-Pérez ◽  
D.A. Cortés-Hernández ◽  
J.M. Almanza-Robles ◽  
D. Mantovani ◽  
P. Chevallier
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Hyperthermia Treatment ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Different Temperatures ◽  
Xrd Patterns

Powders of Mg0.4Ca0.6Fe2O4were prepared by sol-gel using ethylene glycol and Mg, Ca and Fe nitrates as starting materials. Those powders were heat treated at different temperatures (300, 400, 500 and 600 °C) for 30 min. The materials obtained were characterized by X-ray diffraction (XRD) and vibrating sample magnetometry (VSM). The Ca-Mg ferrite with the most appropriate magnetic properties was further analyzed by transmission electron microscopy (TEM). The heating capability of the nanoferrites was also tested via magnetic induction. The XRD patterns of these Ca-Mg ferrites showed a cubic inverse spinel structure. Furthermore, neither traces of hematite nor orthorhombic Ca ferrite phases were detected. Moreover, all the Ca-Mg ferrites are superparamagnetic and the particle size distribution of these Ca-Mg magnetic nanoparticles exhibits an average diameter within the range of 10-14 nm. The needed temperature for hyperthermia treatment was achieved at around 12 min.

Magnetic CoFe2O4/carbon nanotubes composites: fabrication, microstructure and magnetic response

2014 ◽  
Vol 28 (12) ◽  
pp. 1450095 ◽  
Author(s):  
Panfeng Wang ◽  
Jingcai Xu ◽  
Yanbing Han ◽  
Bo Hong ◽  
Hongxiao Jin ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Magnetic Properties ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Targeting Therapy ◽  
X Ray ◽  
Transmission Electron ◽  
Tumor Hyperthermia ◽  
Temperature Time ◽  
Microstructure And Magnetic Properties

By combining the unique microstructure of carbon nanotubes (CNTs) with the good magnetism of CoFe 2 O 4 ferrites, CoFe 2 O 4/CNTs nanocomposites were prepared by the solvothermal method for the application of targeting therapy and tumor hyperthermia. X-ray diffraction (XRD), thermal gravity analysis (TGA), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM) were introduced to study the influence of the solvothermal temperature, time and the CNTs content on the microstructure and magnetic properties of CoFe 2 O 4/CNTs nanocomposites. The diameter of CoFe 2 O 4 nanoparticles coating on the surface of CNTs and the saturation magnetization (Ms) increased with the solvothermal temperature. CoFe 2 O 4/CNTs nanocomposites prepared at 180°C, 200°C and 220°C exhibited superparamagnetism at room temperature, while the samples prepared at 240°C and 260°C presented ferromagnetism. And the solvothermal time and CNTs content slightly affected the microstructure and magnetic properties, Ms and coercivity (Hc) increased slightly with the increasing solvothermal time and the decreasing CNTs content.

Pure and Ca-doped LaCoO3 Nanopowders: Sol-Gel Synthesis, Characterization and Magnetic Properties

2004 ◽  
Vol 848 ◽  
Author(s):  
Lidia Armelao ◽  
Davide Barreca ◽  
Gregorio Bottaro ◽  
Andrea Caneschi ◽  
Claudio Sangregorio ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Chemical Composition ◽  
Auger Electron ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Synthesis

ABSTRACTThis work is focused on the sol-gel synthesis of pure and Ca-doped LaCoO3 nanopowders. The samples were prepared starting from methanolic solutions of cobalt (II) acetate (Co(CH3COO)2·4H2O), lanthanum (III) nitrate (La(NO3)3·6H2O) and calcium (II) acetate (Ca(CH3COO)2·H2O). After solvent evaporation, the obtained powders were dried under vacuum and subsequently treated in air up to 1273 K. The system evolution under thermal annealing was studied by X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM), while the chemical composition was analyzed by X-ray Photoelectron (XPS) and X-ray Excited Auger electron (XE-AES) spectroscopies. The temperature and field dependence of the magnetic properties of the Ca-doped samples were investigated, and compared to those of the corresponding pure LaCoO3 powders.

Preparation, Characterization and Magnetic Property of MFe2O4 (m=Mn, Zn, Ni, Co) Nanoparticles

2013 ◽  
Vol 842 ◽  
pp. 35-38 ◽  
Author(s):  
Li Xia Yang ◽  
Sha Li ◽  
Jing Zhang ◽  
Zhou Chen ◽  
Shi Cheng Xu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Basic Source ◽  
Co Nanoparticles ◽  
Zn Nanoparticles

MFe2O4 (M=Mn, Co, Ni, Zn) Nanoparticles with diameters from 5nm to 30nm have been prepared through a hydrothermal method. In this system, ethanolamine was used as a basic source instead of NaOH. The as-prepared ferrites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). In addition, the magnetic properties of the obtained ferrites have been studied at room temperature, showing that the magentic properties of ferrites closely depended on the chemical composition of M2+.

Facile Sol-Gel Synthesis of Mesoporous TiO2 in Ionic Liquids

2013 ◽  
Vol 389 ◽  
pp. 53-56
Author(s):  
Shu Guo ◽  
Sheng Xu Lu ◽  
Hui Ding ◽  
Zai Feng Shi
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Sol Gel ◽  
Rutile Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylate Groups ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Sol Gel Synthesis

The mesoporous TiO2 particles was conveniently prepared in a room temperature ionic liquid (RTILs) of 1, 3-di-(3-propionyloxy) imdazolium tetrafluoroborate [DiprCOOBF4 system. The obtained materials were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and N2 adsorptiondesorption analysis. XRD patterns revealed that only rutile phase is formed in the RTILs. The TEM micrographs as well as N2 adsorptiondesorption measurements show that the prepared products exhibited wormlike pore structures. The FTIR (Fourier Transform Infrared Spectra) demonstrate the carboxylate groups attach via bidentate or bridging coordination to the TiO2 surface.

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