Unique surface sensitivity to ferro- and antiferromagnetic phases by polarization analysis in synchrotron Mössbauer reflectivity

2021 ◽  
pp. 101521
Author(s):  
R.A. Baulin ◽  
M.A. Andreeva ◽  
L. Häggström ◽  
V.E. Asadchikov ◽  
B.S. Roshchin ◽  
...  
Keyword(s):  
Polarization Analysis ◽  
Surface Sensitivity ◽  
Unique Surface

scholarly journals Channeling in helium ion microscopy: Mapping of crystal orientation

2012 ◽  
Vol 3 ◽  
pp. 501-506 ◽  
Author(s):  
Vasilisa Veligura ◽  
Gregor Hlawacek ◽  
Raoul van Gastel ◽  
Harold J W Zandvliet ◽  
Bene Poelsema
Keyword(s):  
Secondary Electron ◽  
Geometric Model ◽  
Particle Beam ◽  
Surface Layers ◽  
Charged Particle Beam ◽  
Surface Information ◽  
Surface Sensitivity ◽  
Helium Ion ◽  
Ion Microscopy ◽  
Unique Surface

Background: The unique surface sensitivity and the high resolution that can be achieved with helium ion microscopy make it a competitive technique for modern materials characterization. As in other techniques that make use of a charged particle beam, channeling through the crystal structure of the bulk of the material can occur. Results: Here, we demonstrate how this bulk phenomenon affects secondary electron images that predominantly contain surface information. In addition, we will show how it can be used to obtain crystallographic information. We will discuss the origin of channeling contrast in secondary electron images, illustrate this with experiments, and develop a simple geometric model to predict channeling maxima. Conclusion: Channeling plays an important role in helium ion microscopy and has to be taken into account when trying to achieve maximum image quality in backscattered helium images as well as secondary electron images. Secondary electron images can be used to extract crystallographic information from bulk samples as well as from thin surface layers, in a straightforward manner.

Imaging magnetic microstructure with SEMPA

1993 ◽  
Vol 51 ◽  
pp. 1032-1033
Author(s):  
M. H. Kelley ◽  
J. Unguris ◽  
R. J. Celotta ◽  
D. T. Pierce
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Sandwich Structure ◽  
Magnetic Coupling ◽  
Polarization Analysis ◽  
Secondary Electrons ◽  
Magnetic Microstructure ◽  
Escape Depth ◽  
Scanning Electron

By measuring the spin polarization of secondary electrons generated in a scanning electron microscope, scanning electron microscopy with polarization analysis (SEMPA) can directly image the magnitude and direction of a material’s magnetization. Because the escape depth of the secondaries is only on the order of 1 nm, SEMPA is especially well-suited for investigating the magnetization of ultra-thin films and surfaces. We have exploited this feature of SEMPA to study the magnetic microstrcture and magnetic coupling in ferromagnetic multilayers where the layers may only be a few atomic layers thick. For example, we have measured the magnetic coupling in Fe/Cr/Fe(100) and Fe/Ag/Fe(100) trilayers and have found that the coupling oscillates between ferromagnetic and antiferromagnetic as a function of the Cr or Ag spacer thickness.The SEMPA apparatus has been described in detail elsewhere. The sample consisted of a magnetic sandwich structure with a wedge-shaped interlayer as shown in Fig. 1.

Effect of brefeldin A (BFA) on the unique surface coat of pulmonary intravascular macrophages (PIMs) of sheep: Ultrastructural and cytochemical study

1993 ◽  
Vol 51 ◽  
pp. 18-19
Author(s):  
Baljit Singh
Keyword(s):  
Brefeldin A ◽  
Ultrastructural Feature ◽  
Surface Coat ◽  
Anterograde Transport ◽  
Cytochemical Study ◽  
Active Involvement ◽  
Electron Lucent ◽  
Pulmonary Intravascular Macrophages ◽  
Unique Surface

The PIM of sheep, calf, goat and horse has a characteristic ultrastructural feature in the form of a unique, heparin sensitive, globular surface coat present around the plasma membrane with an intervening electron lucent space of 32-40 nm. We previously showed the active involvement of this surface coat in the phagocytosis of tracer material like monastral blue and cationized ferritin. The surface coat is capable of reconstitution in vivo following disruption with heparin. The present study was aimed to investigate whether PIM is the source of surface coat or not. In the recent years the BFA has been extensively used to understand the secretory pathways in the cells because of its ability to cause a rapid and reversible block to the anterograde transport of proteins from the endoplasmic reticulum to the Golgi.Sheep (n=6) were weighed, their plasma volume was calculated indirectly and based on which a sufficient single intravenous dose of BFA was given so as to reach a concentration of 4-5 microgram/ml of plasma.

POLARIZATION ANALYSIS OF THE MAGNETIC DIFFUSE SCATTERING OF Na3Cr2P3O12

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-199-C8-200
Author(s):  
N. Fanjat ◽  
O. Schaerpf ◽  
J. L. Soubeyroux ◽  
A. J. Dianoux ◽  
G. Lucazeau
Keyword(s):  
Diffuse Scattering ◽  
Polarization Analysis

Bubble Electrospinning and Bubble-Spun Nanofibers

2020 ◽  
Vol 14 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Lynn Y. Wan
Keyword(s):  
Surface Tension ◽  
Low Energy ◽  
Efficient Technology ◽  
High Productivity ◽  
Needleless Electrospinning ◽  
Polymeric Nanofibers ◽  
Low Energy Consumption ◽  
Potential Applications ◽  
Surface Morphologies ◽  
Unique Surface

Electrospinning is a highly efficient technology for fabrication of a wide variety of polymeric nanofibers. However, the development of traditional needle-based electrospinning has been hampered by its low productivity and need of tedious work dealing with needles cleaning, installation and uninstallation. As one of the most promising needleless electrospinning means, bubble electrospinning is known for its advantages of high productivity and relatively low energy consumption due to the introduction of a third force, air flow, as a major force overcoming the surface tension. In this paper, the restrictions of conventional electrospinning and the advantages of needleless electrospinning, especially the bubble electrospinning were elaborated. Reports and patents on bubble-spun nanofibers with unique surface morphologies were also reviewed in respect of their potential applications.

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