Structural and Magnetic Properties of the Zn-Mn-O System

2007 ◽  
Vol 555 ◽  
pp. 95-100
Author(s):  
D. Milivojević ◽  
Jovan Blanuša ◽  
V. Spasojević ◽  
V. Kusigerski ◽  
B. Babić-Stojić
Keyword(s):  
Room Temperature Ferromagnetism ◽  
Manganese Concentration ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Mn Oxide ◽  
Different Temperatures ◽  
Electron Paramagnetic

Zn-Mn-O semiconductor crystallites with nominal manganese concentration x = 0.01, 0.02, 0.04 and 0.10 were synthesized by a solid state reaction route using oxalate precursors. Thermal treatment procedure was carried out in air at different temperatures in the range 400 - 900°C. The samples were investigated by X-ray diffraction, magnetization measurements and electron paramagnetic resonance. X-ray analysis reveals that dominant crystal phase in the Zn-Mn-O system corresponds to the wurtzite structure of ZnO. Room temperature ferromagnetism is observed in the Zn-Mn-O samples with lower manganese concentration, x ≤ 0.04, thermally treated at low temperature (500°C). Saturation magnetization in the sample with x = 0.01 is found to be 0.05 μB/Mn. The ferromagnetic phase seems to be developed by Zn diffusion into Mn-oxide grains.

scholarly journals Ferromagnetic behavior of the Zn-Mn-O system

2009 ◽  
Vol 74 (1) ◽  
pp. 71-84 ◽  
Author(s):  
Branka Babic-Stojic ◽  
Dusan Milivojevic ◽  
Jovan Blanusa
Keyword(s):  
Thermal Treatment ◽  
Room Temperature Ferromagnetism ◽  
Ferromagnetic Phase ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Transmission Electron ◽  
Zno Crystal ◽  
Thermally Treated

Polycrystalline Zn-Mn-O samples with nominal manganese concentrations x = 0.01, 0.04 and 0.10 were synthesized by a solid state reaction route using (ZnC2O4?2H2O)1-x and (MnC2O4?2H2O)x. Thermal treatment of the samples was performed in air at temperatures 673, 773, 873, 973 and 1173 K for x = 0.01 and at the temperature 773 K for x = 0.04 and 0.10. The samples were investigated by X-ray diffraction, thermogravimetry, differential thermal analysis, transmission electron microscopy, magnetization measurements and electron paramagnetic resonance. X-Ray diffraction was also performed on MnO2 thermally treated at temperatures 673, 773, 873, 973, 1073 and 1173 K. Room temperature ferromagnetism was observed in the Zn-Mn-O samples with x = 0.01 thermally treated at low temperatures (673 and 773 K) and in the sample with x = 0.04 thermally treated at 773 K. It seems that the ferromagnetic phase could originate from interactions between Mn2+ and acceptor defects incorporated in the ZnO crystal lattice during the thermal treatment of the samples.

ON THE FERROMAGNETIC PHASE TRANSITION IN NANO ZnO:Mn BY ELECTRON PARAMAGNETIC RESONANCE

2009 ◽  
Vol 23 (15) ◽  
pp. 3221-3229 ◽  
Author(s):  
P. VINOTHA BOORANA LAKSHMI ◽  
B. RANGANATHAN ◽  
N. RAJKUMAR ◽  
K. RAMACHANDRAN
Keyword(s):  
Phase Transition ◽  
Electron Paramagnetic Resonance ◽  
Solid State ◽  
Room Temperature ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Ferromagnetic Phase Transition ◽  
Electron Paramagnetic

Nanocrystalline samples of Zn 1-x Mn x O (x = 0.0, 0.01, 0.02, 0.1 and 0.2) were synthesized by solid state reaction and characterized by X-ray diffraction and electron paramagnetic resonance (EPR) at room temperature. EPR studies showed an evidence of ferromagnetism above room temperature.

scholarly journals Electrospun Nanosystems Based on PHBV and ZnO for Ecological Food Packaging

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2123
Author(s):  
Maria Râpă ◽  
Maria Stefan ◽  
Paula Popa ◽  
Dana Toloman ◽  
Cristian Leostean ◽  
...  
Keyword(s):  
Food Packaging ◽  
Spin Trapping ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
Hno3 Solution ◽  
X Ray ◽  
Trapping Method ◽  
Ft Ir ◽  
Doped Zno ◽  
Electron Paramagnetic

The electrospun nanosystems containing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and 1 wt% Fe doped ZnO nanoparticles (NPs) (with the content of dopant in the range of 0–1 wt% Fe) deposited onto polylactic acid (PLA) film were prepared for food packaging application. They were investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), antimicrobial analysis, and X-ray photoelectron spectrometry (XPS) techniques. Migration studies conducted in acetic acid 3% (wt/wt) and ethanol 10% (v/v) food simulants as well as by the use of treated ashes with 3% HNO3 solution reveal that the migration of Zn and Fe falls into the specific limits imposed by the legislation in force. Results indicated that the PLA/PHBV/ZnO:Fex electrospun nanosystems exhibit excellent antibacterial activity against the Pseudomonas aeruginosa (ATCC-27853) due to the generation of a larger amount of perhydroxyl (˙OOH) radicals as assessed using electron paramagnetic resonance (EPR) spectroscopy coupled with a spin trapping method.

Fabrication, characterization and magnetic properties of Na-doped ZnO nanorods

2016 ◽  
Vol 09 (03) ◽  
pp. 1650039 ◽  
Author(s):  
Jingyuan Piao ◽  
Li-Ting Tseng ◽  
Kiyonori Suzuki ◽  
Jiabao Yi
Keyword(s):  
Magnetic Measurements ◽  
Zno Nanorods ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Shallow Donors ◽  
Na Doping ◽  
Transmission Electron ◽  
Doped Zno ◽  
Electron Paramagnetic

Na-doped ZnO nanorods have been fabricated through a hydrothermal method. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses indicate that the d spacing of ZnO increases with increasing doping concentration, suggesting the effective incorporation of dopant Na in the samples. Electron paramagnetic resonance (EPR) measurements indicate that there are shallow donors in pure ZnO samples and the shallow donors are strongly prohibited by Na doping. In addition, the resonance at g = 2.005 suggests the formation of Zn vacancies. Magnetic measurements indicate that pure ZnO is paramagnetic and Na doping leads to ferromagnetism at room temperature. Moreover, 0.5% Na-doped ZnO nanorods exhibits the largest saturation magnetization.

Electronic and Structural Requisites for Catalytic Activity in Copper-Ruthenium Catalysts

1994 ◽  
Vol 368 ◽  
Author(s):  
M. Malaty ◽  
D. Singh ◽  
Noel Vadel ◽  
M.L. Gomez ◽  
M. Palmieri ◽  
...  
Keyword(s):  
Structural Changes ◽  
Supported Catalyst ◽  
Ruthenium Catalysts ◽  
Molecular Techniques ◽  
Oxidation Reactions ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
Different Temperatures ◽  
Electron Paramagnetic ◽  
Reduced Forms

ABSTRACTA system made by combining two non-alloying metals, ruthenium and copper, using alumina as a support was studied. This bimetallic supported catalyst has been used mainly in hydrogenolysis, dehydrogenation and oxidation reactions of hydrocarbons. The samples were characterized by Electron Paramagnetic Resonance Spectrometry (EPR) and X-ray Diffraction (XRD). These two molecular techniques are ideal for studying the electronic and structural changes of the samples at different temperatures and concentrations. Catalytic reactions were performed using the catalyst in the reduced and non-reduced forms on a series of catalytic hydrogenations. A correlation between the electronic, structural and catalytic properties has been made. A correlation of catalytic process to molecular phenomena has yield a better understanding of the catalytic site.

Dinuclear Cu(II) 1,2,3-Triazole-Bridged Complex with Ferromagnetic Coupling

2013 ◽  
Vol 66 (9) ◽  
pp. 1029 ◽  
Author(s):  
Shi-Qiang Bai ◽  
Lu Jiang ◽  
Jing-Lin Zuo ◽  
Chun-Hua Yan ◽  
T. S. Andy Hor
Keyword(s):  
Resonance Spectrum ◽  
Magnetic Measurements ◽  
Ferromagnetic Coupling ◽  
X Ray Diffraction ◽  
Asymmetric Mode ◽  
Paramagnetic Resonance ◽  
Ferromagnetic Interaction ◽  
X Ray ◽  
Electron Paramagnetic ◽  
Weak Ferromagnetic

A new dinuclear Cu(ii) complex [Cu2Cl4(L1)2] (1) (L1 = 1-(2-picolyl)-4-hexyl-1H-1,2,3-triazole) has been synthesised and characterised by single-crystal X-ray diffraction (XRD) and powder XRD, thermogravimetric analysis, electron paramagnetic resonance spectrum, photoluminescence, and magnetic measurements. Complex 1 shows double 1,2,3-triazoles bridging the dinuclear Cu2N4 moiety, in which the bridging N=N bond indicates basal-apical asymmetric mode with 112.6° torsion angle of Cu–N=N–Cu. Different from most azole-bridged dinuclear Cu(ii) with antiferromagnetic couplings, complex 1 shows an intramolecular weak ferromagnetic interaction (J = 0.91 cm–1).

Probing the Structure and Visible Light Photocatalytic Mechanism of LaVO4/TiO2 Composite Using XRD, BET, and EPR

2012 ◽  
Vol 217-219 ◽  
pp. 737-740
Author(s):  
Han Jie Huang
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Visible Light ◽  
Gas Phase ◽  
Spin Trapping ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Photocatalytic Mechanism ◽  
Electron Paramagnetic ◽  
Visible Light Photocatalytic

In this work, a visible light-induced LaVO4/TiO2 composite has been characterized by powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and spin-trapping electron paramagnetic resonance (EPR) to reveal the structure and visible light photocatalytic mechanism for the decompostion of benzene in gas-phase. Based on the experimental results, a visible light-induced photochemical processes on LaVO4/TiO2 are proposed and elucidated.

scholarly journals X-Ray Diffraction, Electron Paramagnetic Resonance and Optical Absorption Study of Bauxite

2014 ◽  
Vol 02 (02) ◽  
pp. 114-120
Author(s):  
Tanguturi Ravindra Reddy ◽  
Krishnan Thyagarajan ◽  
Ovidio Almanza Montero ◽  
Sanapa Reddy Lakshmi Reddy ◽  
Tamio Endo
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Optical Absorption ◽  
Absorption Study ◽  
X Ray Diffraction ◽  
Optical Absorption Study ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Diffraction Electron ◽  
Electron Paramagnetic
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