Thermodynamics and crystallization

Grzegory I, Jun J, Bockowski M, Krukowski S, Wroblewski M, Lucznik B and Porowski S 1995 lll-V nitrides-thermodynamics and crystal growth at high N2 pressure J. Phys. Chem. Solids 56 639... 

As shown in this chapter, the solvent can influence crystal product quality through its effect on crystallization kinetics, solution thermodynamics, and crystal interface structure. However, in many instances, the presence of impurities, reaction by-products, or corrosion products in the commercial system can override the solvent-induced behavior, yielding results different from those obtained in pure solvent. The strong influence of impurities at the parts per million level stems from the unique ability of certain impurities to adsorb at key growth sites on the crystal growth surface, as discussed in detail in Section 3.6. 

The solid solution crystallization is first described by Sanchez IC, Eby RK (1975) Thermodynamics and Crystallization of Random Copolymers. Macromolecules 8 638-642. 

Bogoyavlensky, V.A., Che-Rnova, N.A. Diffusion-limited aggregation A relationship between surface thermodynamics and crystal morphology. Phys. Rev. E 61, 1629 (2000)... 

Sadler DM, Barber M, Lark G, Hill MJ (1986) Twin morphology 2. Measurements of the enhancement in growth due to re-entrant comers. Polymer 27(l) 25-33 Sanchez I, Eby R (1975) Thermodynamics and crystallization of random copolymers. Macromolecules 8(5) 638-641... 

Sanchez 1, Eby R. Thermodynamics and crystallization of random copolymers. Macromolecules 1975 8 638-641. 

Dislocation theory as a portion of the subject of solid-state physics is somewhat beyond the scope of this book, but it is desirable to examine the subject briefly in terms of its implications in surface chemistry. Perhaps the most elementary type of defect is that of an extra or interstitial atom—Frenkel defect [110]—or a missing atom or vacancy—Schottky defect [111]. Such point defects play an important role in the treatment of diffusion and electrical conductivities in solids and the solubility of a salt in the host lattice of another or different valence type [112]. Point defects have a thermodynamic basis for their existence in terms of the energy and entropy of their formation, the situation is similar to the formation of isolated holes and erratic atoms on a surface. Dislocations, on the other hand, may be viewed as an organized concentration of point defects they are lattice defects and play an important role in the mechanism of the plastic deformation of solids. Lattice defects or dislocations are not thermodynamic in the sense of the point defects their formation is intimately connected with the mechanism of nucleation and crystal growth (see Section IX-4), and they constitute an important source of surface imperfection. 

To provide a rational framework in terms of which the student can become familiar with these concepts, we shall organize our discussion of the crystal-liquid transition in terms of thermodynamic, kinetic, and structural perspectives. Likewise, we shall discuss the glass-liquid transition in terms of thermodynamic and mechanistic principles. Every now and then, however, to impart a little flavor of the real world, we shall make reference to such complications as the prior history of the sample, which can also play a role in the solid behavior of a polymer. 

The most important materials among nonlinear dielectrics are ferroelectrics which can exhibit a spontaneous polarization PI in the absence of an external electric field and which can spHt into spontaneously polarized regions known as domains (5). It is evident that in the ferroelectric the domain states differ in orientation of spontaneous electric polarization, which are in equiUbrium thermodynamically, and that the ferroelectric character is estabUshed when one domain state can be transformed to another by a suitably directed external electric field (6). It is the reorientabiUty of the domain state polarizations that distinguishes ferroelectrics as a subgroup of materials from the 10-polar-point symmetry group of pyroelectric crystals (7—9). 

We now apply the thermodynamic and kinetic theory of Chapters 5-8 to four problems making rain getting fine-grained castings growing crystals for semiconductors and making amorphous metals. 

To recapitulate, the legs of the imaginary tripod on which the structure of materials science is assembled are atoms and crystals phase equilibria microstructure. Of course, these are not wholly independent fields of study. Microstructure consists of phases geometrically disposed, phases are controlled by Gibbsian thermodynamics. 

Elyashevich, G. K. Thermodynamics and Kinetics of Orientational Crystallization of Flexible-Chain Polymers. Vol. 43, pp. 207 — 246. 

Thermodynamics and Kinetics of Orientational Crystallization of Flexible-Chain Polymers... 

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