Epitaxial crystallization lattice matching

The epitaxial effect of the KBr surfaces on the nucleation of the y-form crystallites in poly(vinylidene flnoiide) was observed. The acceleration mechanism for y-form crystallization is unknown.It is known that the crystal lattice matching should induce the epitaxial growth of the y-form crystallites on the surfaces of KBr particles. The y-form crystals grow on KBr surfaces with the edge-on lamellar structure, because the lattice of... 

MBE (molecular beam epitaxy), which involves epitaxial growth of thin films on either the same material as substrate (homoepitaxial) or a lattice-matched substrate (heteroepitaxial) the heated substrate reacts with a molecular beam of compounds containing the constituent elements of the semiconductor as well as any dopants the resultant film is essentially a single crystal slow growth rates produce films from a few nanometers thick to at most several hundred nanometers that have very high purity and controlled levels of dopants. 

Growth of various semiconductors onto certain single-crystal substrates has resulted in epitaxial growth in a number of cases. This epitaxy has been well studied for CdS deposition by Lincot et al. [59-63]. Although the epitaxy requires a certain degree of lattice matching between semiconductor and substrate, chemical interactions between the constituents of the deposition solution and the substrate are important as well (discussed in more detail in Chap. 4). It is a reasonable assumption that epitaxial deposition occurs via an ion-by-ion process. Indeed, it has... 

Epitaxial crystallization utilizes some form of lattice (dimensional) and structural (surface topographies) matching of the deposit (usually the polymer) and the substrate crystal. This matching has been demonstrated in a number of ways in the field of polymer crystallization [18] and only the general rules are (briefly) recalled here. 

Experimental determinations of barrier heights on oxide semiconductor interfaces using photoelectron spectroscopy are rarely found in literature and no systematic data on interface chemistry and barrier formation on any oxide are available. So far, most of the semiconductor interface studies by photoelectron spectroscopy deal with interfaces with well-defined substrate surfaces and film structures. Mostly single crystal substrates and, in the case of semiconductor heterojunctions, lattice matched interfaces are investigated. Furthermore, highly controllable deposition techniques (typically molecular beam epitaxy) are applied, which lead to films and interfaces with well-known structure and composition. The results described in the following therefore, for the first time, provide information about interfaces with oxide semiconductors and about interfaces with sputter-deposited materials. Despite the rather complex situation, photoelectron spectroscopy studies of sputter-deposited... 

In the absence of good quality single crystal samples, the physical properties of indium nitride have been measured on non-ideal thin films, typically ordered polycrystalline material with crystallites in the 50 nm to 500 nm range. Structural, mechanical and thermal properties have only been reported for epitaxial films on non-lattice-matched substrates. 

The maximum in catalytic activity observed for the multiphase region of the phase diagram necessarily arises from interactions between the separate phases. The bismuth rich and cerium rich solid solutions can readily form coherent interfaces at the phase boundaries due to the structural similarities between the two phases which can permit epitaxial nucleation and growth. A good lattice match exists between the [010] faces of the compounds, this match is displayed in Figure 6. We have also shown that regions of an [010] face of a Ce doped bismuth molybdate crystal resembles cerium molybdate compos tionally. This means that the interface between the two compounds need not have sharp composition gradients. It is structurally possible for the Bi-rich phase to possess a metal stiochiometry at the surface that matches that of the Ce-rich phase. 

Heterogeneous epitaxy is a specific interfacial crystallization between different polymer pairs due to lattice matching. Heterogeneous epitaxy at interfaces may be an active way to improve the mechanical properties of polymer blends, especially for incompatible systems. The epitaxial growth of HDPE and LLDPE on the... 

The repeating intervals of the phenyl and thiophene units in the TPCO chain approximately match the ionic lattice constant along the < 1 10>kci direction, 0.44 nm. This lattice matching causes the epitaxial nucleation and the growth of the needle crystals to be promoted by the intermolecular interaction due to the partly planar jt-conjugating structure of the thiophene block and also to their moderate molecular diffusion on the surface. 

To summarize, the epitaxial crystallization of iPP and sPP onto crystals of small organic molecules as well as onto each other rests on a lattice and structural match of submolecular features (arrays of methyl groups. 

---