Application of the method of directed orthogonalization to the problem of diffraction on a periodic layer

2019 ◽  
Author(s):  
Dmitri Knyazkov
Keyword(s):  
Periodic Layer

Electron microscopy of crystalline structure in thermotropic random copolymers

1991 ◽  
Vol 49 ◽  
pp. 1054-1055
Author(s):  
Afzana Anwer ◽  
S. Eilidh Bedford ◽  
Richard J. Spontak ◽  
Alan H. Windle
Keyword(s):  
Electron Microscopy ◽  
Crystalline Structure ◽  
Liquid Crystalline ◽  
Elevated Temperatures ◽  
Random Copolymers ◽  
Molecular Characteristics ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Identical Monomer ◽  
Periodic Layer

Random copolyesters composed of wholly aromatic monomers such as p-oxybenzoate (B) and 2,6-oxynaphthoate (N) are known to exhibit liquid crystalline characteristics at elevated temperatures and over a broad composition range. Previous studies employing techniques such as X-ray diffractometry (XRD) and differential scanning calorimetry (DSC) have conclusively proven that these thermotropic copolymers can possess a significant crystalline fraction, depending on molecular characteristics and processing history, despite the fact that the copolymer chains possess random intramolecular sequencing. Consequently, the nature of the crystalline structure that develops when these materials are processed in their mesophases and subsequently annealed has recently received considerable attention. A model that has been consistent with all experimental observations involves the Non-Periodic Layer (NPL) crystallite, which occurs when identical monomer sequences enter into register between adjacent chains. The objective of this work is to employ electron microscopy to identify and characterize these crystallites.

On the spectral simulation of a periodic layer

2008 ◽  
Vol T132 ◽  
pp. 014051
Author(s):  
A M Oparin ◽  
E I Oparina ◽  
O V Troshkin
Keyword(s):  
Spectral Simulation ◽  
Periodic Layer

Electron microscopy of non-periodic layer crystallites in thermotropic random copolymers

1990 ◽  
Vol 25 (6) ◽  
pp. 2727-2736 ◽  
Author(s):  
Richard J. Spontak ◽  
Alan H. Windle
Keyword(s):  
Electron Microscopy ◽  
Random Copolymers ◽  
Periodic Layer

Impossibility of negative group velocities in a periodic layer structure with or without loss

2005 ◽  
Vol 250 (4-6) ◽  
pp. 258-265 ◽  
Author(s):  
Louis Poirier ◽  
Robert I. Thompson ◽  
Alain Haché
Keyword(s):  
Layer Structure ◽  
Negative Group ◽  
Periodic Layer ◽  
Group Velocities

X-Ray Reflectivity Studies of Pt/AlN Multilayered Films

2007 ◽  
Vol 561-565 ◽  
pp. 2095-2098
Author(s):  
Takashi Harumoto ◽  
Ji Shi ◽  
Yoshio Nakamura
Keyword(s):  
Layer Structure ◽  
Bragg Reflection ◽  
X Ray Diffraction ◽  
Multilayered Films ◽  
Sputtering Deposition ◽  
X Ray ◽  
First Order ◽  
Periodic Layer ◽  
Deposited Films ◽  
Very High

Pt/AlN multilayered films fabricated by alternative sputtering deposition were characterized by X-Ray Reflectometry and X-Ray Diffraction. As-deposited films have (111) and (001) preferred orientation for Pt and AlN, respectively. The X-Ray Reflectivity profiles are assigned to the total reflection and Bragg reflections due to periodic layer structure. The Bragg peaks are observed at the 2Theta range beyond 15 degree and the peak intensities increase after annealing. The reflectivity of the first order Bragg reflection is approximately 65% and is stable after annealing at 873K. Simulation of the reflectivity profile has shown roughnesses of the Pt/AlN interfaces are below 0.4nm. X-Ray Diffraction revealed the development of film texture and formation of superlattice by annealing. The latter indicates periodicity of film is very high.

Periodic Layer Slipping in a Sheared Smectic A Cell

2000 ◽  
Vol 347 (1) ◽  
pp. 179-188 ◽  
Author(s):  
N. J. Mottram ◽  
T. J. Sluckin ◽  
S. J. Elston ◽  
M. J. Towler
Keyword(s):  
Smectic A ◽  
A Cell ◽  
Periodic Layer

Diffraction of plane wave at 3-dimensional periodic layer

2018 ◽  
Author(s):  
Dmitri Knyazkov
Keyword(s):  
Plane Wave ◽  
3 Dimensional ◽  
Periodic Layer
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