Shear structures planar defects

Shear structures with one set of planar defects -shear structure... 

Shear structure with two sets of planar defects—block structure... 

Schematic illustration of shear-plane formation. Structure (a) with aligned oxygen vacancies shears to eliminate these vacancies in favour of an extended planar defect in the cation lattice as in (b). % cations oxygen ions are at the mesh intersections...

The extended defect structures that occur in certain non-stoicheiometric compounds have in recent years provided some of the most intriguing problems in solid-state chemistry. The most intensively studied phase showing this class of disorder is Ti02-x> which planar defects known as shear planes have been detected and characterized by electron microscopy. Examples of other simple inorganic compounds containing shear planes are provided by V02 x and The range of... 

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. 

Planar defects surfaces, grain boundaries, small-angle grain boundaries, cell walls, planar stacking faults, antiphase domain walls, shear structures, segregation of impurity atoms to interfaces... 

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