Estimation of three-dimensional mean dihedral angle in a W–Ni–Fe alloy liquid-phase sintered in microgravity

2009 ◽  
Vol 61 (12) ◽  
pp. 1101-1104 ◽  
Author(s):  
W.B. Goodwin ◽  
M. Bharadwaj ◽  
Y. Mao ◽  
A.M. Gokhale ◽  
A. Gurumurthy ◽  
...  
Author(s):  
F. Banhart ◽  
F.O. Phillipp ◽  
R. Bergmann ◽  
E. Czech ◽  
M. Konuma ◽  
...  

Defect-free silicon layers grown on insulators (SOI) are an essential component for future three-dimensional integration of semiconductor devices. Liquid phase epitaxy (LPE) has proved to be a powerful technique to grow high quality SOI structures for devices and for basic physical research. Electron microscopy is indispensable for the development of the growth technique and reveals many interesting structural properties of these materials. Transmission and scanning electron microscopy can be applied to study growth mechanisms, structural defects, and the morphology of Si and SOI layers grown from metallic solutions of various compositions.The treatment of the Si substrates prior to the epitaxial growth described here is wet chemical etching and plasma etching with NF3 ions. At a sample temperature of 20°C the ion etched surface appeared rough (Fig. 1). Plasma etching at a sample temperature of −125°C, however, yields smooth and clean Si surfaces, and, in addition, high anisotropy (small side etching) and selectivity (low etch rate of SiO2) as shown in Fig. 2.


2004 ◽  
Vol 95 (1) ◽  
pp. 3-7 ◽  
Author(s):  
P. Chhillar ◽  
S. Sangal ◽  
A. Upadhyaya

2018 ◽  
Vol 946 ◽  
pp. 012144 ◽  
Author(s):  
V N Naumkin ◽  
A M Lipaev ◽  
V I Molotkov ◽  
D I Zhukhovitskii ◽  
A D Usachev ◽  
...  

2016 ◽  
Vol 72 (8) ◽  
pp. 1219-1222
Author(s):  
Md. Serajul Haque Faizi ◽  
Musheer Ahmad ◽  
Akram Ali ◽  
Vadim A. Potaskalov

The molecular shape of the title compound, C16H12O7, is bent around the central CH2—O bond. The two benzene rings are almost perpendicular to one another, making a dihedral angle of 87.78 (7)°. In the crystal, each molecule is linked to three others by three pairs of O—H...O hydrogen bonds, forming undulating sheets parallel to thebcplane and enclosingR22(8) ring motifs. The sheets are linked by C—H...O hydrogen bonds and C—H...π interactions, forming a three-dimensional network.


Author(s):  
Ramazan Tatsız ◽  
Veli T. Kasumov ◽  
Tuncay Tunc ◽  
Tuncer Hökelek

The asymmetric unit of the title compound, C22H25F2N4O2, contains two crystallographically independent molecules. In one molecule, the two benzene rings are oriented at a dihedral angle of 1.93 (10)° and in the other molecule the corresponding dihedral angle is 7.19 (9)°. The piperidine rings in the two molecules adopt a similar distorted chair conformation, and both have pseudo-mirror planes passing through the N—O bonds. An intramolecular O—H...N hydrogen bond between the hydroxy group and the imine N atom is observed in both molecules. In the crystal, weak C—H...O and C—H...F hydrogen bonds, enclosingR22(6) ring motifs, and weak π–π stacking interactions link the molecules into a three-dimensional supramolecular network, with centroid-to-centroid distances between the nearly parallel phenyl and benzene rings of adjacent molecules of 3.975 (2) and 3.782 (2) Å.


IUCrData ◽  
2017 ◽  
Vol 2 (3) ◽  
Author(s):  
T. Kavitha ◽  
Devaraj Anandkumar ◽  
Perumal Rajakumar ◽  
Srinivasan Bargavi ◽  
Srinivasakannan Lakshmi

In the title compound, C33H48O8, four terminal H atoms of cholic acid are replaced by three acetyl and one terminal alkyne group. All the acetyl residues are twisted with respect to the rings (A, B and C) to which they are attached. The cyclopentane ring D adopts an envelope conformation with the methyl-substituted C atom as the flap. Rings A, B and C have chair conformations. The dihedral angle between the mean planes of rings C and D is 4.70 (11)°. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a three-dimensional structure.


IUCrData ◽  
2017 ◽  
Vol 2 (5) ◽  
Author(s):  
P. Sivakumar ◽  
G. Ezhamani ◽  
S. Israel ◽  
G. Chakkaravarthi

In the title hydrated molecular salt, C6H9N2+·C8H7O3−·2H2O, the cation is protonated at the pyridine N atom. The cation and anion are linked by a pair of N—H...O hydrogen bonds, which generates anR22(8) loop, and the dihedral angle between their ring planes is 16.07 (14)°. The ion pairs are linked by O—H...O hydrogen bonds involving the water molecules, generating a three-dimensional network. Weak C—H...O and aromatic π–π stacking [centroid-to-centroid distance = 3.5874 (17) Å] interactions are also observed.


2013 ◽  
Vol 69 (2) ◽  
pp. o207-o207
Author(s):  
Syeda Sohaila Naz ◽  
Nazar Ul Islam ◽  
M. Nawaz Tahir ◽  
Muhammad Raza Shah

In the title compound, C15H12N2O7, the dihedral angle between the aromatic rings is 4.58 (13)° and the nitro group is rotated from its attached ring by 18.07 (17)°. Intramolecular N—H...O and O—H...O hydrogen bonds generateS(5) andS(6) rings, respectively. In the crystal, molecules are linked by O—H...O hydrogen bonds, generating [001]C(7) chains. The chains are linked by C—H...O interactions, forming a three-dimensional network, which incorporatesR22(7) andR22(10) loops.


2015 ◽  
Vol 71 (5) ◽  
pp. o270-o271 ◽  
Author(s):  
J. Mohana ◽  
M. Divya Bharathi ◽  
G. Ahila ◽  
G. Chakkaravarthi ◽  
G. Anbalagan

In the anion of the title hydrated molecular salt, C9H8N+·C8H4NO6−·H2O, the protonated carboxyl and nitro groups makes dihedral angles of 27.56 (5) and 6.86 (8)°, respectively, with the attached benzene ring, whereas the deprotonated carboxy group is almost orthogonal to it with a dihedral angle of 80.21 (1)°. In the crystal, the components are linked by O—H...O and N—H...O hydrogen bonds, generating [001] chains. The packing is consolidated by weak C—H...N and C—H...O interactions as well as aromatic π–π stacking [centroid-to-centroid distances: 3.7023 (8) & 3.6590 (9)Å] interactions, resulting in a three-dimensional network.


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