Class 12th "SOLID STATE"

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DEFECTS IN SOLIDS
"Any departure from the perfectly ordered arrangement in a crystal is termed as defects in that crystal."

 These are two types of defects in solids or crystals :

(i)  Electronic defects : The electrons and holes in solids gives rise to electronic defects. 
"The error in charge distribution in solids is called electronic defects."
•  These defects are produced when the composition of an ionic crystal doesn't correspond to the exact stoichiometric formula.


(ii)  Atomic defects : The defects caused by the non-arrangement of ions/atom.
These are two types of atomic defects as follows :


[A]  Point Defects : The defects caused by a departure from the periodic arrangement of particles in the vicinity of an atoms. 
These are three types of Point Defects :

1.  Stoichiometric Defects. 

2.  Non-Stoichiometric Defects. 

3.  Impurity Defects. 



[B]  Non-Stoichiometric Defects :

1.  Metal excess defect due to anion vacancies. 

2.  Metal excess defect due to interstitial cation. 

3.  Metal deficiency defect due to cation vacancies. 



[C]  Impurity Defects :

1.  Defects in Cordination solids. 

2.  Defects in Ionic solids. 


 

                        Thank you  ! 

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