Stability of X-ray cellulose crystallite orientation parameters in native cotton with change of location and year of growth

1999 ◽  
Vol 72 (2) ◽  
pp. 269-276 ◽  
Author(s):  
A. V. Moharir ◽  
Lieva Van Langenhove ◽  
Els Van Nimmen ◽  
Johanna Louwagie ◽  
Paul Kiekens
Keyword(s):  
Crystallite Orientation ◽  
X Ray ◽  
Cellulose Crystallite ◽  
Orientation Parameters

Quantifying Multiple Crystallite Orientations and Crystal Heterogeneities in Complex Thin Film Materials

2019 ◽  
Author(s):  
Jonathan Ogle ◽  
Daniel Powell ◽  
Eric Amerling ◽  
Detlef Matthias Smilgies ◽  
Luisa Whittaker-Brooks
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Structural Design ◽  
Grazing Incidence ◽  
Crystallite Orientation ◽  
Miller Index ◽  
X Ray ◽  
X Ray Scattering ◽  
Orientation Distributions ◽  
Orientation Information

<p>Thin film materials have become increasingly complex in morphological and structural design. When characterizing the structure of these films, a crucial field of study is the role that crystallite orientation plays in giving rise to unique electronic properties. It is therefore important to have a comparative tool for understanding differences in crystallite orientation within a thin film, and also the ability to compare the structural orientation between different thin films. Herein, we designed a new method dubbed the mosaicity factor (MF) to quantify crystallite orientation in thin films using grazing incidence wide-angle X-ray scattering (GIWAXS) patterns. This method for quantifying the orientation of thin films overcomes many limitations inherent in previous approaches such as noise sensitivity, the ability to compare orientation distributions along different axes, and the ability to quantify multiple crystallite orientations observed within the same Miller index. Following the presentation of MF, we proceed to discussing case studies to show the efficacy and range of application available for the use of MF. These studies show how using the MF approach yields quantitative orientation information for various materials assembled on a substrate.<b></b></p>

Liquid Crystalline Thermosets As Materials For Microelectronics

1991 ◽  
Vol 227 ◽  
Author(s):  
C. K Ober ◽  
G. G. Barclay
Keyword(s):  
Thermal Expansion ◽  
Liquid Crystalline ◽  
Coefficient Of Thermal Expansion ◽  
High Thermal Stability ◽  
Isotropic Phase ◽  
X Ray Diffraction ◽  
Primary Interest ◽  
Functional Monomers ◽  
X Ray ◽  
Orientation Parameters

ABSTRACTNew liquid crystalline thermosets have been prepared from end-functional monomers and oligomers of varying molecular weight. Both triazine and epoxy networks were explored. Of primary interest was the exploitation of the mesophase properties of these networks for developing polymers with high thermal stability and low coefficients of thermal expansion (CTE). Curing was carried out either within the nematic mesophase or the isotropic phase of the prepolymers. Transition temperatures associated with the mesophase were observed to change after curing under these two sets of conditions. The networks with the highest crosslink density were found to exhibit the lowest CTE values. Crosslinking of these thermosets was also carried out in the presence of a 13.5 Tesla magnetic field to determine the effect of orienting fields on the curing of the LC network. Orientation parameters as measured by wide angle x-ray diffraction were as high as 0.6. Values of the coefficient of thermal expansion as low as 15 ppm were achieved in the aligned direction. Of the two resin types, those with the triazine crosslinks had the lowest thermal expansion coefficient. Other thermal properties of these networks will be discussed.

The correlation between X-ray orientation parameters and strength of fibers in native cotton

1992 ◽  
Vol 44 (11) ◽  
pp. 1913-1919 ◽  
Author(s):  
A. V. Moharir ◽  
Johanna Louwagie ◽  
Lieva Van Langenhove ◽  
Paul Kiekens
Keyword(s):  
X Ray ◽  
Orientation Parameters

Strontium Barium Niobate Thin Films Prepared by Pulsed Laser Deposition

1994 ◽  
Vol 361 ◽  
Author(s):  
Y. Liu ◽  
C.W. Ong ◽  
P.W. Chan ◽  
C.L. Choy
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Crystallite Orientation ◽  
Strontium Barium ◽  
Film Composition ◽  
X Ray

ABSTRACTStrontium barium niobate Sr0.55Ba0.45Nb2O6 thin films were prepared on Si (111) substrates by pulsed laser deposition (PLD). The film composition was determined as a function of the fluence φ and wavelength λ of the laser beam, the oxygen ambient pressure Po2 and the substrate temperature Ts. The results show that the film composition is very close to that of the target, and is almost independent of φ from 1 to 8 J cm−2, λ = 355, 532 and 1064 nm, Po2 from 0 to 150 mTorr, and Ts from 25 to 700°C. These results suggest that PLD is excellent for preparing SBN films with compositions congruent to that of the target. The x-ray diffraction data show that all the samples deposited at room temperature are amorphous. The x-ray diffraction results also indicate that the samples deposited at 700°C have a tungsten-bronze-(TB-) type structure with preferred crystallite orientation, while the room-temperature-deposited samples after annealing at 800°C for 30 minutes are polycrystalline and have random crystallite orientation.

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