14 - Defects in ionic solids( Frenkel defect and Schottky defect. )

Описание: Ionic solids must always maintain electrical neutrality. So, the number of cations is equal to the number of anions.
Rather than simple vacancy defect or interstitial defect, they show Frenkel defect and Schottky defect.
Frenkel defect is a type of point defect also known as dislocation defect in which, smaller ions like cations are dislocated from its normal site to an interstitial site (space).
Thus, it creates a vacancy defect in the original site and an interstitial defect at the new location. It does not change the density of the solid.
Frenkel defect is usually seen in ionic solids with a large difference in the size of the cations and anions e.g., Zinc sulphide, Silver chloride, Silver bromide and Silver iodide show this type of defect due to small size of Ag+ and Zn2+ ions.

Schottky defect is a type of vacancy defect in a crystal lattice named after Walter H. Schottky.

The number of missing cations and anions are same and hence the substance remains neutral.

It decreases the density and stability of the substance and increases electrical conductivity.
This defect occurs in solids in which the size of cations and anions do not diffe



r much.

Number of such defects is significantly high in ionic solids. Example: Sodium chloride, potassium chloride, Cesium chloride. In Sodium chloride, there is one schottky defect per 1016 ions.

Silver bromide shows both Frenkel and Schottky defect


#edutech #indianeducation #learn #educational#learningapp #teach #globaleducation #elearning#qualityeducation #educationmatters 
#teaching
#learning
#facts
#support
#goals
like
#nonprofit
#career
#educationmatters#technology

#edutech #indianeducation #learn #educational #learningapp #teach #globaleducation #elearning #qualityeducation #educationmatters
#jee #neet #neet2022 #neet2021 #neetmotivation #neet2023 #neetexam
#neet2023 #preparation #cat #cat #entrance #entranceexam #globaleducation #indianeducation #qualityeducation #medical #entrance #entranceexam