Magnetic Structures of 2D and 3D Nanoparticles

Author(s):  
Jean-Claude Serge Levy
2021 ◽  
Author(s):  
Matteo Faganello ◽  
Manuela Sisti ◽  
Sid Fadanelli ◽  
Silvio Sergio Cerri ◽  
Francesco Califano ◽  
...  

<p><span>In space and astrophysical plasmas magnetized coherent structures continuously emerge as an outcome of the nonlinear dynamics. These structures are characterized  by the presence of localized strong current density peaks. Here we present a statistical study of the development of such structures resulting in different hybrid-Vlasov 3D-3V simulations of plasma turbulence. In particular, we make use of different methods to characterize the global shape of the 3D structures. Furthermore, we study the local magnetic configuration inside and outside current peak regions, comparing the statistics in the two cases. Finally, we discuss correlations between characteristic dimensions of the current structures and current density, marking the difference between magnetic structures in 2D and 3D simulations.<br></span></p>


1994 ◽  
Vol 144 ◽  
pp. 365-367
Author(s):  
E. V. Kononovich ◽  
O. B. Smirnova ◽  
P. Heinzel ◽  
P. Kotrč

AbstractThe Hα filtergrams obtained at Tjan-Shan High Altitude Observatory near Alma-Ata (Moscow University Station) were measured in order to specify the bright rims contrast at different points along the line profile (0.0; ± 0.25; ± 0.5; ± 0.75 and ± 1.0 Å). The mean contrast value in the line center is about 25 percent. The bright rims interpretation as the bases of magnetic structures supporting the filaments is suggested.


Author(s):  
D. J. Barber ◽  
R. G. Evans

Manganese (II) oxide, MnO, in common with CoO, NiO and FeO, possesses the NaCl structure and shows antiferromagnetism below its Neel point, Tn∼ 122 K. However, the defect chemistry of the four oxides is different and the magnetic structures are not identical. The non-stoichiometry in MnO2 small (∼2%) and below the Tn the spins lie in (111) planes. Previous work reported observations of magnetic features in CoO and NiO. The aim of our work was to find explanations for certain resonance results on antiferromagnetic MnO.Foils of single crystal MnO were prepared from shaped discs by dissolution in a mixture of HCl and HNO3. Optical microscopy revealed that the etch-pitted foils contained cruciform-shaped precipitates, often thick and proud of the surface but red-colored when optically transparent (MnO is green). Electron diffraction and probe microanalysis indicated that the precipitates were Mn2O3, in contrast with recent findings of Co3O4 in CoO.


Author(s):  
P.M. Rice ◽  
MJ. Kim ◽  
R.W. Carpenter

Extrinsic gettering of Cu on near-surface dislocations in Si has been the topic of recent investigation. It was shown that the Cu precipitated hetergeneously on dislocations as Cu silicide along with voids, and also with a secondary planar precipitate of unknown composition. Here we report the results of investigations of the sense of the strain fields about the large (~100 nm) silicide precipitates, and further analysis of the small (~10-20 nm) planar precipitates.Numerous dark field images were analyzed in accordance with Ashby and Brown's criteria for determining the sense of the strain fields about precipitates. While the situation is complicated by the presence of dislocations and secondary precipitates, micrographs like those shown in Fig. 1(a) and 1(b) tend to show anomalously wide strain fields with the dark side on the side of negative g, indicating the strain fields about the silicide precipitates are vacancy in nature. This is in conflict with information reported on the η'' phase (the Cu silicide phase presumed to precipitate within the bulk) whose interstitial strain field is considered responsible for the interstitial Si atoms which cause the bounding dislocation to expand during star colony growth.


2021 ◽  
Author(s):  
Ruoyang Liu ◽  
Ke Tian Tan ◽  
Yifan Gong ◽  
Yongzhi Chen ◽  
Zhuoer Li ◽  
...  

Covalent organic frameworks offer a molecular platform for integrating organic units into periodically ordered yet extended 2D and 3D polymers to create topologically well-defined polygonal lattices and built-in discrete micropores and/or mesopores.


2012 ◽  
Author(s):  
Michael Sackllah ◽  
Denny Yu ◽  
Charles Woolley ◽  
Steven Kasten ◽  
Thomas J. Armstrong

Author(s):  
Denny Yu ◽  
Michael Sackllah ◽  
Charles Woolley ◽  
Steven Kasten ◽  
Thomas J. Armstrong
Keyword(s):  

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