TIT# Complete SAXS data analysis and synthesis of lamellar
two-phase systems. Deduction of a simple model for the layer
statistics
AUT# Stribeck, N.
SOU# J. Phys. IV (1993), 3(C8), 507-10
LOC# xv017 @selbst.ftx
CLA#
COM#
APP#
MAT#
ABS# A structural model for the analysis of small-angle x-ray scattering
(SAXS) data from lamellar two-phase systems is proposed and applied
on data sets from three injection-molded poly(ethylene
terephthalate) (PET) samples. The concept of data analysis is based on
Ruland's interface distribution function (IDF). The suggested model
is defined by few parameters of physical meaning. It unifies the well
known concepts of an ensemble of nonuniform stacks, finite stack
height and one-dimensional paracrystalline disorder in an analysis
expression. In order to deduce this expression, the notion of an
inhomogeneous structure within the sample is mathematical treated in terms
of "compansion", a general superposition principle. Its mathematical
equivalent in one dimension is the Mellin convolution. The theory of
the Mellin convolution may be used to find analysis functions even for
the convoluted. An example is given, which in future work may be
used to describe the thickness distributions of amorphous and crystalline
layers. In the application part of this study Gaussians are used to
describe the thickness distributions in each local stack. The
introduction of compansion adds one extra parameter, which describes
the heterogeneity of the sample. Compansion makes the global
thickness distributions become more asym.