Inherent structure transition surface

Typical surfaces observed in Ising model simulations are illustrated in Fig. 2. The size and extent of adatom and vacancy clusters increases with the temperature. Above a transition temperature (T. 62 for the surface illustrated), the clusters percolate. That is, some of the clusters link up to produce a connected network over the entire surface. Above Tj, crystal growth can proceed without two-dimensional nucleation, since large clusters are an inherent part of the interface structure. Finite growth rates are expected at arbitrarily small values of the supersaturation. 

The studies have shown that irrespective of the composition of the initial mixture, as a result of uniform distribution of components in the structure of samples, the shape of their adsorption isotherms is transformed gradually from the typical isotherm for one individual component to the isotherm for the second component. In this case, as the content of the second component, having a higher sorption capacity, increases, transitional isotherms accumulate features inherent in its structure the micro- and mesopore volume, limiting sorption capacity Vs, and specific surface area Ssp increase. The latter increases because of the fact that along with development of porosity of samples, their more open structure accessible to adsorbate molecules is formed. 

The primary difficulty inherent in this issue is the small niunber of materials with suitable crystal structures and lattice constants. Some transition metals and ceramics, such as Ni, Cu, Fe, and cBN (Table 5, Ch. 3), are the few isostructural materials with sufficiently similar lattice constants (mismatch <5%). In addition, the extremely high surface energies of diamond (ranging from 5.3 to 9.2 J m for the principle low index planes) and the existence of interfacial misfit and strain energies between diamond films and non-diamond substrates constitute the primary obstacles in forming oriented two-dimensional diamond nuclei. Earlier attempts to grow heteroepitaxial diamond on the transition metals were not successful. The reasons may be related to the high solubility/ mobility of C in/on the metals (for example, Fe, Co, or the... 

Transition metals generally have the highest surface free energy, whereas noble metals and semiconductors have substantially lower surface energies. This implies that even if growing of material A on material B works fine, the opposite will not work—a common problem in the fabrication of multilayers with their inherently symmetric structure. Another frequently encountered problem is that of the possibility of interdiffusion at the interface and/or chemical reactions between the deposit and the substrate. It is well known that, especially with the very reactive materials Si and Ge, both can happen, depending on temperature and growth conditions. 

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