Internal pressure effect on cathodoluminescence enhancement of ZnS:Mn2+ synthesized by a sealed vessel

2007 ◽  
Vol 22 (10) ◽  
pp. 2838-2844 ◽  
Author(s):  
B.J. Park ◽  
W.B. Im ◽  
W.J. Chung ◽  
H.S. Seo ◽  
J.T. Ahn ◽  
...  
Keyword(s):  
Synthesis Method ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Synthesis Conditions ◽  
Epr Signal ◽  
Xrd Patterns ◽  
Electron Paramagnetic ◽  
Mn Concentration

ZnS:Mn2+ phosphors were synthesized by a modified solid-state reaction method. In the synthesis method, a sealed vessel is used, where heat and pressure are simultaneously utilized. The effects of various synthesis conditions such as temperature, Mn concentration, and pressure on the cathodoluminescence (CL) were investigated. Among them, pressure had an effect on CL property as much as others. It was observed that CL intensities of ZnS:Mn2+ phosphors increased with the increase of pressure and the best sample showed higher intensity than that of a commercial one by 180%. X-ray diffraction (XRD) and electron paramagnetic-resonance (EPR) were used to understand the enhancement. No change of XRD patterns was observed but the full width at half-maximum (FWHM) of the most intense cubic (111) peak of ZnS:Mn2+ decreased with the increase of pressure. EPR signal intensity of Mn2+ increased with the increase of pressure. The improved crystallinity and more substitution of Zn2+ with Mn metal were believed to be responsible for the enhancement.

X-RAY DIFFRACTION AND ELECTRON PARAMAGNETIC RESONANCE STUDIES OF A Bi4Sr2.5Ca2.5Cu4Ox SUPERCONDUCTING PHASE

1989 ◽  
Vol 03 (17) ◽  
pp. 1319-1325
Author(s):  
TH. LEVENTOURI ◽  
N. GUSKOS ◽  
M. CALAMIOTOU ◽  
O. PAPAGEORGIOU ◽  
S. PARASKEVAS ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Local Symmetry ◽  
Solid State Reaction Method ◽  
Superconducting Phase ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Electron Paramagnetic

We report a study of a low T c phase of the bismuth superconductor. A nominally Bi 4 Sr 2.5 Ca 2.5 Cu 4 O x compound was produced by the solid state reaction method with a T c = 80 K . X-ray diffraction studies show that the structure is very similar to the structure of the 4:3:3:4 composition with indications of small amounts of other phases. Electron paramagnetic resonance spectroscopy gives a strong Cu 2+ signal at temperatures above T c . We make a comparison between the local symmetry of the Cu 2+ ion complexes in this Bi sample and in the Y–Ba–Cu–O superconductor we had studied before.

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.

scholarly journals Influence of Li2CO3 addition on electrical and magnetic properties of Ni0.6Mg0.4Fe2O4

2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Low Frequency ◽  
Solid State Reaction Method ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Frequency Regime ◽  
Xrd Patterns

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.

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.

Quantification of mobilized copper(II) levels in micronized copper-treated wood by electron paramagnetic resonance (EPR) spectroscopy

Holzforschung ◽  
2013 ◽  
Vol 67 (7) ◽  
pp. 815-823 ◽  
Author(s):  
Wei Xue ◽  
Pierre Kennepohl ◽  
John N.R. Ruddick
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Epr Spectroscopy ◽  
Treated Wood ◽  
Spectral Parameters ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Acid Reaction ◽  
Epr Signal ◽  
Electron Paramagnetic ◽  
Reference Samples

Abstract Sapwood sawdust from southern pine was treated with micronized copper (MC) under various conditions and the mobilized copper(II) (Cumob) concentrations were determined in the treated wood by electron paramagnetic resonance (EPR) spectroscopy. The spectral parameters for the copper sulfate (CuSO4)-treated sapwood and those of the MC-treated sapwood were very similar. A linear correlation was found between the intensities of copper (Cu) EPR spectra and those of Cu energy-dispersive X-ray fluorescence spectroscopy in a series of CuSO4-treated sapwood reference samples. Thus, the EPR signal intensities could be reliably correlated to the mass of reacted Cu present using this calibration curve. The amount of the Cumob in sawdust treated by MC suspensions increased during the first 2–3 days after the initial treatment and then reached a maximum during the 7-day monitoring period. In the case of the treatment with MC alone or MC azole, an increased MC concentration led to an elevated amount of Cu (to a maximum of ∼0.23% Cu) solubilized by the sapwood. If the wood was treated with MC quat, the Cumob initially increased, but at higher concentrations the Cumob content decreased, due to the interference by the quat cobiocide on the acid reaction between the wood and the basic Cu carbonate. An examination of commercially-treated wood confirmed the laboratory observations.

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 Synthesis of Na-Doped Lithium Metatitanate and Its Absorption for Carbon Dioxide

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Liu Zhirong ◽  
Zhang Huan ◽  
Wang Yun ◽  
Zhan Xinxing
Keyword(s):  
Carbon Dioxide ◽  
Solid State Reaction Method ◽  
Absorption Capacity ◽  
Absorption Kinetics ◽  
X Ray Diffraction ◽  
Carbon Dioxide Absorption ◽  
Reaction Method ◽  
X Ray ◽  
Xrd Patterns ◽  
The Relationship

Na-doped lithium metatitanate (Na-doped Li2TiO3) absorbent was doped with Na2CO3and lithium metatitanate (Li2TiO3) was prepared by a solid-state reaction method from mixture of TiO2and Li2CO3. The Na-doped lithium metatitanate was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and surface area. Carbon dioxide absorption on Na-doped lithium metatitanate was investigated using TG-DTA. The results reveal an increase of the CO2absorption capacity of the Na-doped materials with respect to pure Li2TiO3. XRD patterns of the doped samples suggest a limited substitution of Li by Na atoms within the Li2TiO3structure. The results of experimental and modeling work were summarized to better understand the relationship between the sorbent microstructure and carbon dioxide absorption kinetics.

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).

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