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Studies two-dimensional lattice models of the Peierls type. Nonlinear interaction of atoms within interface regions; Presentation of an evolution algorithm.

In this paper we analyze hypersingular integral equations of the Peierls type specified on the whole real axis. The method of "approximate approximations" [Maz'ya, Proceedings of the Eighth Conference on the Mathematics of Finite Elements and Applications, VIII, MAFELAP 1993, Brunel University, 1994, pp. 107-104] is employed in order to produce numerical solutions of high accuracy, and the results are applied to problems in the theory of dislocations. The critical Peierls stress is evaluated for different configurations of dislocations and for different types of the interatomic force law. [ABSTRACT FROM AUTHOR]

Lattice-matched III-V compound semiconductor-based heterostructures have played a very important role in the development of high-performance semiconductor devices. The main reason for this is the fact that the lattice constant of AlAs and GaAs are nearly equal and epitaxial layers of AlxGa1-x As can be grown on GaAs with very high quality of the interfaces. Since the bandgap of AlxGa1-xAs is larger than that of pure GaAs, and since it can be changed to any desired value over a large range by changing the concentration , the heterojunctions have been used with great success for improving the existing devices and for developing new devices. It is due to these advantages that extensive work has been done on the III--V-compound-based epitaxial layers and superlattices for device applications (for example Weisbuch (1987) and other articles in the same book).
The properties of bulk crystalline Ge--Si alloys were investigated many years ago (Glickman 1955, 1958, Paul and Warschauer 1958, Dismukes et al. 1964, Feldman et al. 1966, Kline et al. 1968, Renucci et al. 1971, Brya 1973) and several papers have also appeared more recently (Mitchard and McGill 1982, Takeda et al. 1983, Krishnamurthy and Sher 1985, Alonso et al. 1989, Amano et al. 1987). Depending on the composition, the bandgap of the alloy varies from 11 to 07 eV which corresponds to the wavelength range from about 1 to 15 m (Paul and Warschauer 1958). This is a very useful range for many bipolar devices, for discrete opto-electronic devices and for integrated opto-electronics on silicon. In principle, the bandgap engineering using GexSi1-x alloys makes it possible to construct heterostructures to improve the performance of the bipolar and other devices, and to fabricate superlattices and to dope them selectively to obtain high carrier mobilities. However, in the past the potential of GexSi1-x alloys... [ABSTRACT FROM AUTHOR]

Demonstrates a sensitive form of acoustic microscopy which reveals the underlying patterns of stress. The use of an isotropic elastic medium; The discovery that stress-induced anisotropies affect wave polarizations and phases; The interference between waves that would, in the absence of stress, remain in phases; The range of size of objects whose stress can be imaged.

Examines work hardening and strain relaxation in strained-layer buffers. Generation of the process driving force; Impact of stress fluctuations on dislocations; Consideration of the energy required for activation of the layer local sources.