Cations are present in the interstitial sites in __________.


In Frenkel defect which is also known as dislocation defect, the smaller ions (usually the cations) get dislocated from its normal lattice site to an interstitial site, therefore resulting a vacancy defect in the normal site (vacancy for cation) and simultaneously an interstitial defect in the new location of the cation.


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On the other hand (ii) Schottky defect (iii) Vacancy defect (iv) Metal deficiency defect do not necessarily deal with cations.


In (ii) Schottky defect the number of missing cations and anions are equal in order to maintain electrical neutrality in the crystal and thus decreases density.



(iii)Vacancy defect occurs in case of any kind of vacancy in the crystal.


And last (iv) Metal deficiency defect is not even a stoichiometric defect like the other options given. It is rather a non- stoichiometric defect that deals with less amount of metal as compared to the ideal stoichiometric proportion (loss of positive charge).

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