Question

HI.can any 1 tell me about crystal defects?

Answer 1

A perfect crystal, with every atom in the correct position, rarely exists. All crystals have some sort of defect. Defects contribute to the mechanical properties of metals.

There are basic classes of crystal defects:

POINT DEFECTS: These are places where an atom is missing or irregularly placed in the lattice structure. Point defects include lattice vacancies, self-interstitial atoms, substitution impurity atoms, and interstitial impurity atoms.

LINE DEFECTS OR LINEAR DEFECTS: These are groups of atoms in irregular positions. Linear defects are commonly called dislocations. Disclinations are line defects corresponding to "adding" or "subtracting" an angle around a line. This means that on tracking the crystal orientation around the line defect, you get a rotation.

PLANAR DEFECTS: These are interfaces between homogeneous regions of the material. Planar defects include grain boundaries, stacking faults and external surfaces.

Hope this answers your question...☺

Answer 2

defects are majorly stochiometric and non stochiometric
frankel,schottky,impurity are the stochiometric defects
they dont alter the stochiometry of the crystal
defects like metal deficiency(f-centers) alter stochiometry of compound and are called non stochiometric