Microdomain repeat distances

Although the microdomain description is adequate for many compounds, for some phases a more accurate picture is obtained if they are described in terms of two (or more) mutually interacting subsystems. The distribution of atom/vacancies, octahedral tilt, distortion or similar features may not follow a strict crystallographic repeat distance but may be modulated into a wave-like repetition, the wavelength of which is a function of composition, preparation conditions and so on. As an example, suppose that the unit cell for a perovskite has instead of octahedra with alternate tilts +

[Pg.75]

Copolymer Used X-ray scattering. Microdomain measured repeat distance D oc theoretical D oc Hashimoto et al. 1980 Matsushita et al. 1990 Ohta and Kawasaki 1986... 

The microdomain size Di and lattice repeat distance d of periodically organized microdomains have the following approximate molecular mass dependence ... 

After numerous experimental studies it now seems to have been reasonably well established that for AB- and ABA-type block copolymers containing polystyrene and polyisoprene (or polybutadiene) the microdomain size, Dj, and lattice repeat distance d, of periodically organized microdomains have the approximate molecular weight dependence " ... 

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