The Microdefects, Magnetic Properties and Electron Characters of Fe-Ga Alloys

2017 ◽  
Vol 373 ◽  
pp. 167-170
Author(s):  
Ding Kang Xiong ◽  
H.Q. Wei ◽  
W.T. Liu ◽  
Yu Yang Huang ◽  
Wen Deng

The microdefects, magnetic magnetization curves and electric characters of Fe100-xGax (x=16, 17, 18, 19, 20) were investigated by the means of X-ray diffraction, VSM modular on PPMS, positron lifetime spectroscopy and electric paramagnetic resonance spectroscopy. The X – ray diffraction patterns show that the Fe100-xGax alloys is similar to that of α – Fe, but the peaks move to low angle slightly. The result indicates Ga entered the iron lattice and the larger radium lead to the changing of the patterns. Positron lifetime spectra show that the intensity of the defects of the Fe100-xGax alloys varies obviously with different Ga content. The magnetizing curves were measured to check the saturation magnetization at room temperature. The variations of saturation magnetization do not monotonic decrease as expect with the increasing of Ga. When x=18, the magnetization is maximum; the minimum is x=20 because of the lowest iron content. The electron paramagnetic resonance spectrum shows that the peaks become narrower when the x decreases from 20 to 16. These results indicate that the addition of Ga has effect on the 3d electrons of Fe.

Synthesis ◽  
2018 ◽  
Vol 50 (18) ◽  
pp. 3671-3678
Author(s):  
Didier Bourissou ◽  
Amos Rosenthal ◽  
Sonia Mallet-Ladeira ◽  
Ghenwa Bouhadir

Two new P-stabilized boryl radicals [Ph2P(naph)BAr] (Ar = Tip and Ter) have been prepared and characterized by electron paramagnetic resonance spectroscopy. These radicals are persistent for several days in solution at room temperature. The high steric congestion at boron does not prevent radical reactivity. Two different types of dimerization equilibrium have been observed. The structures of the dimers have been unambiguously established by X-ray diffraction crystallography.


1989 ◽  
Vol 03 (17) ◽  
pp. 1319-1325
Author(s):  
TH. LEVENTOURI ◽  
N. GUSKOS ◽  
M. CALAMIOTOU ◽  
O. PAPAGEORGIOU ◽  
S. PARASKEVAS ◽  
...  

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.


2020 ◽  
Vol 73 (3) ◽  
pp. 137
Author(s):  
Fateme Akhlaghi Bagherjeri ◽  
Chris Ritchie ◽  
Robert W. Gable ◽  
Gary Bryant ◽  
Colette Boskovic

The preference for incorporation of molybdenum over tungsten into specific sites of a family of yttrium-arsenotungstates with amino acid ligands prompted exploration of the incorporation of other metals, affording three new vanadium-containing (V/W and V/Mo/W) analogues: K2(GlyH)10[As4(V2W2)W44Y4O160(Gly)8(H2O)12]·11Gly (1), (MBAH)9(L-NleH)3[As4(V2W2)W44Y4O160(L-Nle)8(H2O)12] (2), and (MBAH)9(L-NleH)3[As4(V2W2)Mo2W42Y4O160(L-Nle)8(H2O)12] (3) (Gly=glycine and L-Nle=l-norleucine, MBAH=4-methylbenzylammonium). These hybrid polyoxometalates all possess a tetrametallic oxo-bridged {VIV2WVI2} central core surrounded by an amino acid-ligated cyclic metal-oxo framework. X-Ray photoelectron, UV-visible reflectance, and electron paramagnetic resonance spectroscopy, together with metal analysis, confirm the incorporation of vanadium into the polyoxometalates, while single crystal X-ray diffraction analysis supports the location of the vanadium atoms in the central core.


Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 695 ◽  
Author(s):  
Ramesh P. Sivasankaran ◽  
Nils Rockstroh ◽  
Carsten R. Kreyenschulte ◽  
Stephan Bartling ◽  
Henrik Lund ◽  
...  

MoS2/C3N4 (MS-CN) composite photocatalysts have been synthesized by three different methods, i.e., in situ-photodeposition, sonochemical, and thermal decomposition. The crystal structure, optical properties, chemical composition, microstructure, and electron transfer properties were investigated by X-ray diffraction, UV-vis diffuse reflectance spectroyscopy, X-ray photoelectron spectroscopy, electron microscopy, photoluminescence, and in situ electron paramagnetic resonance spectroscopy. During photodeposition, the 2H MoS2 phase was formed upon reduction of [MoS4]2− by photogenerated conduction band electrons and then deposited on the surface of CN. A thin crystalline layer of 2H MoS2 formed an intimate interfacial contact with CN that favors charge separation and enhances the photocatalytic activity. The 2H MS-CN phase showed the highest photocatalytic H2 evolution rate (2342 μmol h−1 g−1, 25 mg catalyst/reaction) under UV-vis light irradiation in the presence of lactic acid as sacrificial reagent and Pt as cocatalyst.


2009 ◽  
Vol 23 (15) ◽  
pp. 3221-3229 ◽  
Author(s):  
P. VINOTHA BOORANA LAKSHMI ◽  
B. RANGANATHAN ◽  
N. RAJKUMAR ◽  
K. RAMACHANDRAN

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.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2123
Author(s):  
Maria Râpă ◽  
Maria Stefan ◽  
Paula Popa ◽  
Dana Toloman ◽  
Cristian Leostean ◽  
...  

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.


2017 ◽  
Vol 866 ◽  
pp. 199-203
Author(s):  
Chidchanok Chainej ◽  
Suparut Narksitipan ◽  
Nittaya Jaitanong

The aims of this research were study the microstructures and mechanical properties for partial replacement of cement with Fly ash (FA) and kaolin waste (KW). Ordinary Portland cement were partially replaced with FA and KW in the range of 25-35% and 10-25% by weight of cement powder. The kaolin waste was ground for 180 minutes before using. The specimen was packing into an iron mold which sample size of 5×5×5 cm3. Then, the specimens were kept at room temperature for 24 hours and were moist cured in the incubation lime water bath at age of 3 days. After that the specimens were dry cured with plastic wrap at age of 3, 7, 14 and 28 days. After that the compounds were examined by x-ray diffraction patterns (XRD) and the microstructures were examined by scanning electron microscopy (SEM). The compressive strength was then investigated.


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