SYNTHESIS AND CHARACTERIZATION OF ZINC FERRITE BY XRD, VSM AND ELECTRON SPIN RESONANCE TECHNIQUES

2012 ◽  
Vol 27 (04) ◽  
pp. 1250213 ◽  
Author(s):  
PRANABA K. NAYAK ◽  
R. JOTHIRAMALINGAM
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Zinc Ferrite ◽  
Spinel Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Spin Resonance ◽  
Co Precipitation ◽  
Substantial Change

In this report, the synthesis of zinc ferrite ( ZnFe 2 O 4) by co-precipitation method has been presented along with its subsequent characterization by using X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and electron spin resonance (ESR) techniques. The obtained XRD results of as-synthesized sample indicates the cubic spinel phase formation, which was confirmed from the XRD data of the above calcined sample at 1000°C. By using VSM, a complex magnetic structure was observed with substantial change on calcined sample. The ESR result of zinc ferrite sample studied at room temperature was found to be significantly different from that of the low temperature results, especially after heat-treatment.

Photocatalytic Activity of Fe-Doped ZnO/Montmorillonite Nanocomposite for Degradation of Malachite Green

2015 ◽  
Vol 827 ◽  
pp. 19-24 ◽  
Author(s):  
Nur Afifah ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh
Keyword(s):  
Photocatalytic Activity ◽  
Malachite Green ◽  
Organic Dyes ◽  
Uv Light ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Resonance ◽  
Doped Zno ◽  
Co Precipitation

In this study, the photocatalytic activity of pure Fe- doped ZnO and Fe- doped ZnO/Montmorillonite nanocomposite has been investigated for the degradation of malachite green under UV light irradiation. Both photocatalysts were synthesized using co-precipitation method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier-transform infrared absorption, and electron spin resonance. The results showed that the photocatalytic efficiency is better in the presence of montmorillonite compared to pure Fe- doped ZnO. To detect the possible reactive species involved in degradation of organic dyes control experiments with introducing scavengers into the solution of organic dyes were carried out. It is found that electron plays an important role in the degradation of malachite green.

Electron Spin Resonance Characterization of Defects at Interfaces in Stacks of Ultrathin High-κ Dielectric Layers on Silicon

2003 ◽  
Vol 786 ◽  
Author(s):  
A. L. Stesmans ◽  
V.V. Afanas'ev
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Dielectric Layers ◽  
Growth Standard ◽  
Spin Resonance ◽  
Dielectric Interfaces ◽  
Standard Quality

ABSTRACTElectron spin resonance (ESR) analysis of (100)Si/SiOx/ZrO2, (100)Si/Al2O3 and Si/HfO2 structures with nm-thin dielectric layers deposited by different chemical vapor deposition procedures reveals, after hydrogen detachment, the presence of the trivalent Si dangling-bond-type centers Pb0, Pb1 as prominent defects in all entities. This Pb0, Pb1 fingerprint, generally unique for the thermal (100)Si/SiO2 interface, indicates that the as-deposited (100)Si/metal oxides interface is basically Si/SiO2-like. Though sensitive to the deposition process, the Pb0 density is found to be substantially larger than in standard (100)Si/SiO2. As probed by the Pb- type center properties, the Si/dielectric interfaces of all structures are under enhanced (unrelaxed) stress, typical for low temperature Si/SiO2 growth. Standard quality thermal Si/SiO2 properties in terms of Pb signature may be approached by appropriate annealing (≥ 650°C) in vacuum in the case of (100)Si/SiOx/ZrO2. Yet, O2 ambient appears required for Si/Al2O3 and Si/HfO2. It appears that Si/high-κ metal oxide structures with device grade quality interfaces can be realized with sub-nm thin SiOx interlayers. The density of fast interface states closely matches the Pb0 density variations, suggesting the center as the dominant fast interface trap. They may be efficiently passivated in H2 at 400 °C.

Microstructure Characterization of Metal Mixed Oxides

MRS Advances ◽  
2017 ◽  
Vol 2 (64) ◽  
pp. 4025-4030 ◽  
Author(s):  
T. Kryshtab ◽  
H. A. Calderon ◽  
A. Kryvko
Keyword(s):  
Mixed Oxides ◽  
Profile Analysis ◽  
Atomic Resolution ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Reconstruction Procedure ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Co Precipitation

ABSTRACTThe microstructure of Ni-Mg-Al mixed oxides obtained by thermal decomposition of hydrotalcite-like compounds synthesized by a co-precipitation method has been studied by using X-ray diffraction (XRD) and atomic resolution transmission electron microscopy (TEM). XRD patterns revealed the formation of NixMg1-xO (x=0÷1), α-Al2O3 and traces of MgAl2O4 and NiAl2O4 phases. The peaks profile analysis indicated a small grain size, microdeformations and partial overlapping of peaks due to phases with different, but similar interplanar spacings. The microdeformations point out the presence of dislocations and the peaks shift associated with the presence of excess vacancies. The use of atomic resolution TEM made it possible to identify the phases, directly observe dislocations and demonstrate the vacancies excess. Atomic resolution TEM is achieved by applying an Exit Wave Reconstruction procedure with 40 low dose images taken at different defocus. The current results suggest that vacancies of metals are predominant in MgO (NiO) crystals and that vacancies of Oxygen are predominant in Al2O3 crystals.

scholarly journals Characterization of manganese in coal by electron spin resonance.

1985 ◽  
Vol 34 (5) ◽  
pp. 243-247 ◽  
Author(s):  
Junichi SHIDA ◽  
Mamoru ITOH ◽  
Tateaki OGATA ◽  
Hitoshi KAMADA
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Spin Resonance
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