Comment on “Cleavage surface of the BaFe2−xCoxAs2and FeySe1−xTexsuperconductors: A combined STM plus LEED study”

2012 ◽  
Vol 86 (16) ◽  
Author(s):  
M. Cordin ◽  
P. Amann ◽  
A. Menzel ◽  
E. Bertel ◽  
M. Baranov ◽  
...  
Keyword(s):  
Cleavage Surface

Studies of Circular DNA Using a New Electron Microscopic Technique

1973 ◽  
Vol 31 ◽  
pp. 596-597
Author(s):  
C. N. Gordon
Keyword(s):  
Electron Microscopy ◽  
Aqueous Salt Solution ◽  
Contour Length ◽  
Cleavage Surface ◽  
Mica Substrate ◽  
Electron Microscopic ◽  
Replica Technique ◽  
Circular Dna ◽  
Transmission Electron ◽  
Electron Microscopic Technique

Gordon and Kleinschmidt have described a new preparative technique for visualizing DNA by electron microscopy. This procedure, which is a modification of Hall's “mica substrate technique”, consists of the following steps: (a) K+ ions on the cleavage surface of native mica are exchanged for Al3+ ions by ion exchange. (b) The mica, with Al3+ in the exchange sites on the surface, is placed in a dilute aqueous salt solution of DNA for several minutes; during this period DNA becomes adsorbed on the surface. (c) The mica with adsorbed DNA is removed from the DNA solution, rinsed, dried and visualized for transmission electron microscopy by Hall's platinum pre-shadow replica technique.In previous studies of circular DNA by this technique, most of the molecules seen were either broken to linears or extensively tangled; in general, it was not possible to obtain suitably large samples of open extended molecules for contour length measurements.

SREM observation of the interaction between the in-situ deposited Pd small particles and MgO cleavage surface

1986 ◽  
Vol 44 ◽  
pp. 382-383
Author(s):  
H.-J. Ou
Keyword(s):  
Electron Microscopy ◽  
Small Particle ◽  
Small Particles ◽  
Cleavage Surface ◽  
Metallic Particles ◽  
Microscopy Technique ◽  
Ceramic Surfaces ◽  
Reflection Electron Microscopy ◽  
New Perspective

The understanding of the interactions between the small metallic particles and ceramic surfaces has been studied by many catalyst scientists. We had developed Scanning Reflection Electron Microscopy technique to study surface structure of MgO hulk cleaved surface and the interaction with the small particle of metals. Resolutions of 10Å has shown the periodic array of surface atomic steps on MgO. The SREM observation of the interaction between the metallic particles and the surface may provide a new perspective on such processes.

Adsorption of Water Vapour on a Cleavage Surface of Lithium Fluoride

1962 ◽  
Vol 1 (4) ◽  
pp. 234-234 ◽  
Author(s):  
Koreo Kinosita ◽  
Hiroomi Kojima ◽  
Hideshi Yokota
Keyword(s):  
Water Vapour ◽  
Lithium Fluoride ◽  
Cleavage Surface ◽  
Adsorption Of Water

Soil Particle Surface Charge

2016 ◽  
Author(s):  
Garrison Sposito
Keyword(s):  
Layer Structure ◽  
Particle Surface ◽  
Electronic Charge ◽  
Isomorphic Substitution ◽  
Hexagonal Symmetry ◽  
Cleavage Surface ◽  
Octahedral Sheet ◽  
Weak Hydrogen Bonds ◽  
Lower Valence ◽  
The Right

Structural charge arises on the surfaces of soil mineral particles in which either cation vacancies or isomorphic substitutions of cations by cations of lower valence occur. The principal minerals bearing structural charge are therefore the micas (Section 2.2), the 2:1 clay minerals (Section 2.3), or the Mn(IV) oxide, birnessite (Section 2.4). These three classes of mineral are all layer type and the cleavage surface on which their structural charge is manifest is a plane of O ions. The plane of O ions on the cleavage surface of a layer-type aluminosilicate is called a siloxane surface.This plane is characterized by hexagonal symmetry in the configuration of its constituent O ions, as shown at the top of Fig. 2.3 and, more explicitly, on the right side of Fig. 2.4, where a portion of the siloxane surface of the micas is depicted. Reactive molecular units on the surfaces of soil particles are termed surface functional groups. The functional group associated with the siloxane surface is the roughly hexagonal (strictly speaking, ditrigonalbecause the hexagonal symmetry is distorted when the tetrahedral sheet is fused to an octahedral sheet to form a layer) cavity formed by six corner-sharing silica tetrahedra. This cavity has a diameter of about 0.26 nm. The reactivity of the siloxane cavity depends on the nature of the electronic charge distribution in the layer structure. If there are no nearby isomorphic cations substitutions to create a negative charge, the O ions bordering the siloxane cavity function as an electron cloud donor that can bind molecules weakly through the van der Waals interaction. These interactions are akin to those underlying the hydrophobic interaction, discussed in Section 3.5, because the O in the siloxane surface can form only very weak hydrogen bonds with water molecules. Therefore, uncharged patches on siloxane surfaces may be considered hydrophobic regions to a certain degree, with, accordingly, an attraction for hydrophobic organic molecules. However, if isomorphic substitution of Al3+ by either Fe2+ or Mg2+ occurs in the octahedral sheet, the resulting structural charge is manifest on the siloxane cavities, as discussed in Section 2.3.

An inclusion of magnetite in diamond

1924 ◽  
Vol 20 (107) ◽  
pp. 245-247
Author(s):  
L. J. Spencer
Keyword(s):  
South Africa ◽  
Cleavage Surface ◽  
Crystal Face ◽  
Sharp Image ◽  
Tile Surface

A Minute, black fragment of material, taken by Dr. J. R. Sutton from a cavity exposed on a cleavage-surface of a colourless diamond from Bultfontein mine, Kimberley, South Africa, was sent by him for determination. It is black with a sub-metallic lustre and in parts a bronzed tarnish; and is quite opaque even on the edges. The form is roughly that of a triangular chip, measuring 11/2 by 11/4 mm. with a greatest thickness of about 1/2 mm. The weight is about 1 milligram. Tile surface shows a small and uneven to granular fracture. On one portion there is a good crystal-face which reflects a sharp image ; and on one part of this face there is a stepped growth with striae at 60°.

On the diathermancy of Antimonite

1903 ◽  
Vol 13 (62) ◽  
pp. 342-347
Author(s):  
A. Hutchinson
Keyword(s):  
Cleavage Surface ◽  
Direct Sunlight ◽  
Orthorhombic System ◽  
Elliptic Polarization ◽  
Polarization Of Light

A determination of the constants of elliptic polarization of light reflected from a fresh cleavage surface of antimonite enabled Professor P. Drude to calculate two of the indices of refraction of this substance as 5.17 and 4.49 respectively. Instead, however, of the symmetry-axes of the crystal, regarded as belonging to the orthorhombic system, coinciding with the principal vibration directions in the plane (010), he found that the latter were inclined to the former lines at angles which varied in different observations between 2.6° and 15.4°. These observations, which indicate that the symmetry of antimonite is of the oblique or anorthie type, stand in opposition to those of Professor O. Mügge, who found that exceedingly thin flakes of antimonite placed between crossed nicols in direct sunlight transmitted sufficient light of a deep red colour to enable him to determine the extinction as straight.

Nanorelief of the natural cleavage surface of triglycine sulphate crystals with substitutional and interstitial impurities

2011 ◽  
Vol 56 (6) ◽  
pp. 1070-1076 ◽  
Author(s):  
N. V. Belugina ◽  
R. V. Gainutdinov ◽  
A. L. Tolstikhina ◽  
V. V. Dolbinina ◽  
N. I. Sorokina ◽  
...  
Keyword(s):  
Cleavage Surface ◽  
Triglycine Sulphate ◽  
Interstitial Impurities

Electronic and structural properties of bulk arsenopyrite and its cleavage surfaces – a DFT study

RSC Advances ◽  
2015 ◽  
Vol 5 (3) ◽  
pp. 2013-2023 ◽  
Author(s):  
Juliana C. M. Silva ◽  
Heitor A. De Abreu ◽  
Hélio A. Duarte
Keyword(s):  
Electronic Properties ◽  
Structural Properties ◽  
Density Functional ◽  
Plane Waves ◽  
Dft Study ◽  
Cleavage Surface ◽  
Surface Formation ◽  
Structural And Electronic Properties ◽  
Electronic And Structural Properties

We have investigated the structural and electronic properties of arsenopyrite and its cleavage surface formation using a density functional/plane waves method. QTAIM and ELF were applied for investigating the nature of the bonding in arsenopyrite.

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