imperfect crystal

imperfect crystal

[im¦pər‚fekt ′krist·əl]
(crystallography)
A crystal in which the regular, periodic structure is interrupted by various defects.
References in periodicals archive ?
The predominance of [beta]-phase in PVDF-60 might be attributed to the formation of more imperfect crystal in the membrane matrix (Figure 4).
The 10-year forecast, introduced under Bill Clinton, is certainly an imperfect crystal ball.
The sand and the other ingredients are put in a pot along with any imperfect crystal, where it bubbles away and melts.
As the time frame for crystallization is small, an imperfect crystal structure and only a very small crystal superstructure are mainly found in this edge layer.
The presence of solid entities on the surface of a growing mineral commonly causes imperfect crystal growth.
On the basis of DSC and XRD analyses, we suggested that PTFE fibrils would be imperfect crystal. Its crystal became homogeneous, and the grain of fibril was refined in the process of orientation.
It is generally recognized that a polymer of high molecular weight has better mechanical properties because of a high density of chain entanglement [28, 29] with relatively imperfect crystal structure.
X-ray diffraction on imperfect crystals, Willey, New York.
Yet imperfect crystals are quite common, and not infrequently illustrated in crystal drawings from the older literature.
Imperfect crystals have a significantly lower area of melting peak than do primary crystals.
Compared with the neat sample, the spherulite size of nylon-6 was significantly increased and imperfect crystals formed after introducing PEO component.
The second recrystallization peak just before the melting point is quite interesting and may indicate the possibility of merging small imperfect crystals, which are formed by initial cold crystallization at [T.sub.c1].