SCHOTTKY DEFECT It is discovered by German scientist Schottky 1930. This type of defect is observed in ab type crystal when equal number of cations and anions are missed from their lattice sites. A Pair holes or vacancies created at their original lattice sites. Since number of cations and anions are same so crystal remain electrically neutral.
Condition To Observe Schottky Defect
(i) Ionic compounds with high coordination number.
(ii) Ionic compounds in which cations and anions are not much different their sizes.
e.g. NaCl, KCl ,CsCI, KBr, AgBr
Consequences Of Schottky Defect
(i) Density of crystal decreases due to the presence of holes.
(ii) The stability of crystal decreases due to the large number of holes, which lowers that lattice energy
(iii) Electrical conductivity increases as holes are conductive in nature.
(iv) Entropy of the crystal increases.
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