Boundaries stacking fault

A plan-view TEM image showed a uniform contrast, indicating excellent quality of the AIN. No high angle boundaries, stacking faults or twinned regions were observed. 

Planar defects include grain boundaries, stacking faults, and twins. These defects are formed during ion implantation and thermal and processing. All three types of planar defects are enclosed by a single dislocation or by an array of dislocations separating the faulted area from the normal area or delineating the misorientation between various areas of the semiconductor. 

A suitable classification of crystalline defects can be achieved by first considering the so-called point defects and then proceeding to higher-dimensional defects. Point defects are atomic defects whose effect is limited only to their immediate surroundings. Examples are vacancies in the regular lattice, or interstitial atoms. Dislocations are classified as linear or one-dimensional defects. Grain boundaries, phase boundaries, stacking faults, and surfaces are two-dimensional defects. Finally, inclusions or precipitates in the crystal matrix can be classified as three-dimensional defects. 

Most of our discussion will be confined to point defects in ionic solids (ceramics). Line defects, commonly referred to as dislocations, are characterized by displacements in the periodic structure of the lattice in certain directions. They play their most important role in the plastic deformation of metals. Planar defects include free surfaces, grain boundaries, stacking faults, and crystallographic shear planes. 

Extended defects range from well characterized dislocations to grain boundaries, interfaces, stacking faults, etch pits, D-defects, misfit dislocations (common in epitaxial growth), blisters induced by H or He implantation etc. Microscopic studies of such defects are very difficult, and crystal growers use years of experience and trial-and-error teclmiques to avoid or control them. Some extended defects can change in unpredictable ways upon heat treatments. Others become gettering centres for transition metals, a phenomenon which can be desirable or not, but is always difficult to control. Extended defects are sometimes cleverly used. For example, the smart-cut process relies on the controlled implantation of H followed by heat treatments to create blisters. This allows a thin layer of clean material to be lifted from a bulk wafer [261. 

Stacking faults thereby providing barriers to sHp. If carbides are allowed to precipitate to the point of becoming continuous along the grain boundaries, they often initiate fracture (see Fracture mechanics). A thorough discussion of the mechanical properties of cobalt alloys is given in References 29 and 30 (see also Refractories). 

Using the constructed potentials the y-surface for the (111) plane was calculated. (For more details see Girshick and Vitek 1995). T e lowest energy minimum on this surface corresponds to the ideal Llo structure. However, there are three different metastable stacking fault type defects on (111) the antiphase boundary (APB), the complex stacking fault (CSF) and the superlattice intrinsic stacking fault (SISF). The displacements... 

There are two questions that needed to be answered here. (1) How can the ligand access the interiors of big prismatic particles to lead to the smaller particles and (2) Why do the ligands lead to smaller particles at all While it is difficult to conclusively find answers to both the questions, the first step in the digestive ripening procedure offers some leads. (1) The big prismatic particles obtained by the reverse micelle-based synthesis are loaded with defects such as twinning boundaries and stacking faults. 

Finally, two-dimensional defects can occur in crystals. There are two categories of planar defects stacking faults and grain boundaries. 

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