Synthesis and Magnetic Properties of CoFe2O4 Nano-Particles

2010 ◽  
Vol 148-149 ◽  
pp. 998-1002 ◽  
Author(s):  
Xiao Yun Chen ◽  
Hua Li ◽  
Yue Zeng Su ◽  
Zi Shan Huang ◽  
He Zhou Liu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Hydrothermal Process ◽  
Nano Particles ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Water Ratio

Spinel CoFe2O4 nano-particles were synthesized by hydrothermal traditionally and Ethylene Glycol (EG) assisted hydrothermal process originally. The effects of reaction temperatures from 140°C to 200°C, different OH- provider and EG/water ratio on the nano-particles’ structure, morphology and magnetic properties of composition were studied by X-ray diffractometer (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The possible mechanism for the effects on the properties was also discussed in details. The results showed that NaAC as OH- provider and higher EG/water ratio in solvent were benefit for getting smaller CoFe2O4 nano-particles. And existence of EG is also important to remove the α-Fe2O3 phase.

TEM Study of FePt and FePt:C/FePt Composite Double-Layered Thin Films

2013 ◽  
Vol 275-277 ◽  
pp. 1952-1955
Author(s):  
Ling Fang Jin ◽  
Xing Zhong Li
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Magnetic Properties ◽  
Composite Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

New functional nanocomposite FePt:C thin films with FePt underlayers were synthesized by noneptaxial growth. The effect of the FePt layer on the ordering, orientation and magnetic properties of the composite layer has been investigated by adjusting FePt underlayer thickness from 2 nm to 14 nm. Transmission electron microscopy (TEM), together with x-ray diffraction (XRD), has been used to check the growth of the double-layered films and to study the microstructure, including the grain size, shape, orientation and distribution. XRD scans reveal that the orientation of the films was dependent on FePt underlayer thickness. In this paper, the TEM studies of both single-layered nonepitaxially grown FePt and FePt:C composite L10 phase and double-layered deposition FePt:C/FePt are presented.

Magnetic Properties of E21-base Co3AlC and the Correlation with the Ordering of Carbon Atoms and Vacancies

2004 ◽  
Vol 842 ◽  
Author(s):  
Yoshisato Kimura ◽  
Fu-Gao Wei ◽  
Hideyuki Ohtsuka ◽  
Yoshinao Mishima
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Vibrating Sample Magnetometer ◽  
Hrtem Image ◽  
Atomic Configuration ◽  
Phase Domain ◽  
Transmission Electron ◽  
Anti Phase Boundary ◽  
Local Atomic Configuration

ABSTRACTTargeting to develop E21 Co3AlC based heat resistant alloys, phase stability of E21 Co3AlC and (Co, Ni)3AlC has been investigated together with the magnetic properties of E21’ Co3AlC0.5 which is formed by the extra ordering of carbon atoms accompanying anti-phase boundary (APB). The correlation of ferromagnetism with APB in E21’ Co3AlC0.5 was evaluated using single crystals by high-resolution transmission electron microscopy (HRTEM) and vibrating sample magnetometer. Anti-phase domain (APD) size affects the ferromagnetism: for instance, the saturation magnetization becomes larger as the APD size is smaller. Local atomic configuration at APB was clearly observed by HRTEM image.

Research on Structural Properties of FePt: C Thin Films with FePt Underlayers

2013 ◽  
Vol 385-386 ◽  
pp. 7-10
Author(s):  
Ling Fang Jin ◽  
Hong Zhuang
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Structural Properties ◽  
Composite Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Nonepitaxially grown double-layered films were synthesized with a FePt: C composite layer on top of continuous FePt underlayer. The thickness of FePt was changed from 2 nm to 14 nm. Nanostructures, crystalline orientations and the effect of FePt underlayer on the ordering, orientation and magnetic properties of the thin films were investigated by transmission electron microscopy (TEM) and x-ray diffraction (XRD). XRD confirmed the formation of the ordered L10phase for 5 nm FePt: C film with FePt thickness decreased to 5 nm. TEM studies of FePt:C composite L10phase and double-layered deposition FePt:C/FePt were presented.

Synthesis of ZnO2 Nanocrystals Produced by Hydrothermal Process

2009 ◽  
Vol 1242 ◽  
Author(s):  
R. Esparza ◽  
A. Aguilar ◽  
A. Escobedo-Morales ◽  
C. Patiño-Carachure ◽  
U. Pal ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Peroxide ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Process ◽  
High Resolution Electron Microscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Zinc Peroxide ◽  
20 Nm

ABSTRACTZinc peroxide (ZnO2) nanocrystals were directly produced by hydrothermal process. The nanocrystals were synthesized using zinc acetate as precursor and hydrogen peroxide as oxidant agent. The ZnO2 powders were characterized by X-ray powder diffraction and transmission electron microscopy. The results of transmission electron microscopy indicated that the ZnO2powders consisted of nanocrystals with diameters below to 20 nm and a faceted morphology. High resolution electron microscopy observations have been used in order to the structural characterization. ZnO2 nanocrystals exhibit a well-crystallized structure.

scholarly journals Sintesis Nanopartikel Nickel Ferrite (NiFe2O4) dengan Metode Kopresipitasi dan Karakterisasi Sifat Kemagnetannya (Halaman 20 s.d. 25)

2015 ◽  
Vol 19 (56) ◽  
Author(s):  
Muflihatun ◽  
Siti Shofiah ◽  
Edi Suharyadi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fourier Transform ◽  
Nickel Ferrite ◽  
Fourier Transform Infrared ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Nanopartikel Nikel Ferit (NiFe2O4) telah disintesis dengan metode kopresipitasi dengan memvariasi konsentrasi NaOH dan suhu sintesis. Struktur kristal, ukuran partikel, dan morfologi dari sampel dianalisa menggunakan X-ray diffraction (XRD) dan transmission electron microscopy (TEM). Ukuran butir pada konsentrasi NaOH 3, 5, dan 10 M masing-masing adalah 5,7; 4,3; dan 4,2 nm, sedangkan pada suhu 60, 80, dan 150°C berturut-turut adalah 4,2; 4,9; dan 5,5 nm. Analisa fourier transform infrared (FTIR) menunjukkan dua puncak serapan pada rentang ~400-600 cm-1 yang terkait dengan site oktahedral dan tetrahedral pada struktur NiFe2O4. Sifat magnetik NiFe2O4 hasil analisa vibrating sample magnetometer (VSM) menunjukkan bahwa sampel berperilaku ferromagnetik dengan nilai koersivitasnya pada rentang 42-47 Oe. Sampel dengan variasi konsentrasi NaOH, koersivitasnya cenderung menurun dengan menurunnya ukuran partikel. Sementara sampel dengan variasi suhu, semakin kecil ukuran partikel, koersivitasnya cenderung meningkat. Pada 15 kOe, nilai magnetisasi terbesar (6,17 emu/g) diperoleh pada sampel dengan rasio fasa α-Fe2O3 paling rendah.

Hydrothermal Synthesis of Zn2(MoO4)(SeO3) and Photocatalytic Applications

2013 ◽  
Vol 385-386 ◽  
pp. 16-18
Author(s):  
Yan Zhong Zhen ◽  
Dan Jun Wang ◽  
Feng Fu ◽  
Gang Lin Xue
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
Hydrothermal Process ◽  
Experimental Result ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Applications ◽  
Simple Hydrothermal Process

A novel mixed metal molybdates, Zn2(MoO4)(SeO3) 1 has been synthesized by a simple hydrothermal process. Samples obtained are characterized using powder and single crystal X-ray diffraction (XRD), transmission electron microscopy (TEM). Furthermore, the photocatalytic performances of samples obtained are investigated for degradation of RhB under visible light irradiation. photocayalysis experimental result has illustrated that the compound exhibits good photocatalysis.

Preparation and characteristics of 90° rotated biepitaxial Fe3O4 thin films

2002 ◽  
Vol 17 (8) ◽  
pp. 1985-1991 ◽  
Author(s):  
Hiroshi Matsuda ◽  
Hiroshi Sakakima ◽  
Hideaki Adachi ◽  
Akihiro Odagawa ◽  
Kentaro Setsune
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Electron Diffraction ◽  
Grain Boundary ◽  
Seed Layer ◽  
Tunneling Magnetoresistance ◽  
X Ray ◽  
Transmission Electron

In-plane 90° rotated biepitaxial Fe3O4 thin films have been successfully prepared onto MgO (110) substrates using a CeO2 seed layer and their microstructure, electric, and magnetic properties were investigated. From the x-ray φ-scan measurements, the in-plane epitaxial relations were determined as 〈110〉Fe3O4//〈110〉MgO and 〈001〉Fe3O4//〈001〉MgO for the no-seeded Fe3O4 layer, and 〈001〉Fe3O4//〈110〉MgO and 〈110〉Fe3O4//〈001〉MgO for the CeO2 (110) seeded Fe3O4 layer. The CeO2 seed layer was found to rotate the upper Fe3O4 lattice at 90° upon normal axis to the layer against the no-seeded Fe3O4. The transmission electron microscopy and electron diffraction analyses revealed that the transition region of the biepitaxial Fe3O4 boundary between CeO2-seeded and no-seeded portions consisted of columnarlike polycrystalline grains. The Fe 3O4 films exhibited single-crystallinelike electric and magnetic properties, however, substantial spin-dependent-tunneling magnetoresistance across the 90° grain boundary was not observed even in the antiparallel situation for each Fe3O4 portion.

SYNTHESIS OF MoS2/GRAPHENE NANOCOMPOSITE BY FACILE ULTRASONIC-ASSISTED HYDROTHERMALMETHOD

2019 ◽  
Vol 57 (6) ◽  
pp. 703
Author(s):  
Long Le Ngoc ◽  
Kien Pham Trung ◽  
Khai Tran Van
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hexagonal Phase ◽  
Hydrothermal Process ◽  
Thin Layers ◽  
X Ray ◽  
Practical Applications ◽  
Transmission Electron ◽  
Ultrasonic Assisted ◽  
Graphene Nanocomposite

In this report, thin layers of MoS2 were in-situ incorporated into graphene oxide (GO) to form MoS2/graphene nanocomposite by a facile ultrasonic-assisted hydrothermal method. X-ray Diffraction (XRD) and Raman analysis revealed that the as-synthesized MoS2 nanosheets crystalized in hexagonal phase 2H-MoS2 while High Resolution Transmission Electron Microscopy (HRTEM) images confirmed that MoS2 layers with average thickness of ~5–6 nm (6–8 layers) attached on the edges and surfaces of graphene sheets with high density and uniform shape restacking in three-dimensional (3D) architectures. The Scanning Transmission Electron Microscopy – Energy Dispersive X-ray spectrum (STEM-EDX) investigation further confirmed the low impurity of MoS2/graphene composite, and the well repairing of defects in GO surfaces during the hydrothermal process. Our approach is promising for a scalable, inexpensive, and accurate strategy to fabricate state-of-the-art materials with a certain structure for various practical applications such as electrode material for Lithium battery or supercapacitor.

Fabrication of In2O3 Oxide Semiconductor Nano-Particles Using Apoferritin

2005 ◽  
Vol 873 ◽  
Author(s):  
Mitsuhiro Okuda ◽  
Ichiro Yamashita ◽  
Kenji Iwahori ◽  
Hideyuki Yoshimura
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Nano Particles ◽  
Oxide Semiconductor ◽  
Cavity Size ◽  
X Ray ◽  
Transmission Electron ◽  
Lattice Space ◽  
High Resolution Tem

AbstractIn2O3 nanoparticles were fabricated in the cavity of the cage-shaped protein, apoferritin by utilizing a quick chemical reaction of indium oxide. Horse spleen apoferritin in the solution of indium ions buffered at pH 9.5 was incubated for 30 minutes. The transmission electron microscopy (TEM) observation with aurothioglucose staining showed that cores were formed in the apoferritin cavity. The sizes of cores were regulated by the cavity size and their diameters were below 7nm. Energy dispersion X-ray analysis (EDX) indicated that indium was contained in the cores. The high-resolution TEM (HR-TEM) revealed that cores are single or poly crystalline and the lattice space was consistent with that of In2O3. These results confirmed that the In2O3 cores were successfully formed in the apoferritin cavity.

Hydrothermal Synthesis and Photoluminescence of Eu2−xSmxSn2O7 (x = 0–2.0) Nanophosphors

2008 ◽  
Vol 8 (3) ◽  
pp. 1427-1431
Author(s):  
Hongliang Zhu ◽  
Enze Zhu ◽  
Hong Yang ◽  
Dalai Jin ◽  
Deren Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid Solutions ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
Efficient Energy Transfer ◽  
X Ray ◽  
Transmission Electron ◽  
Pyrochlore Type ◽  
The Eu

Eu2–xSmxSn2O7 (x = 0, 0.1, 0.5, 1.0, 1.5, and 2.0) solid solutions were successfully synthesized by a simple, mild hydrothermal process. The crystal structure, particle size, and chemical composition of the solid solutions were characterized by X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy. X-ray diffraction patterns and transmission electron microscopy images reveal that all the products were cubic pyrochlore-type Eu2–xSmxSn2O7 nano-crystals with the diameter of ∼20 nm. Due to efficient energy transfer from Sm3+ to Eu3+, the Eu2–xSmxSn2O7 (x = 0.1, 0.5, 1.0, and 1.5) nanocrystals exhibited strong 5D0 → 7F1 photoluminescence emission of Eu3+. The dominant 5D0 → 7F1 transition revealed good monochromaticity and low distortion of the Eu2–xSmxSn2O7 nanophosphors.

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