Define point defect? Don't spam.
Answers
Answer:
Defect or Imperfection:-
Any departure from perfectly ordered arrangement of the constituent particles in the crystal called imperfection or defect.
The defects in the crystal are arises when crystallization takes place at the fast or moderate rates because the constituent particles does not get sufficient time to arrange in perfect order.
There are mainly two types of defects:-
Point defect:-When the deviation or irregularities exists from ideal arrangement around a point or an atom in a crystalline substance the defect is called the point defect.
Line defect:- When the deviation from the ideal arrangement exists in the entire row of lattice points the defect is called as line defect.
Types of the point defects:-
1. Stoichiometric defects
2. Non stoichiometric defects
3. Impurity defects
Stoichiometric defect:-
If imperfection in the crystal are such that the ratio between cation and onions remains same. Stoichiometry of substance do not disturbed defect is called stoichiometric defect these defects are of the following types.
1. Vacancy defect:-
When is in a crystalline substance, some of the lattice sites are vacant the crystal is said to have vacancy defect it results in decrease of density of substance.
2. Interstitial defect:-
When some extra constituent particles are present in the interstitial site the crystal is said to be have interstitial defect.
This defect increases density of the crystal
These above types of defects are shown only by non – ionic solids.
3. Schottky defect:-
If in an ionic crystal of the type A+B- equal number of cations and anions are missing from the lattice site. So that electrical neutrality is remained is called schottky defect.
Compounds exhibiting schottky defect are NaCl, KCl
Which compounds have small difference in size of cation and anions show defect.
Frenkel defect:- If an ion is missing, from its lattice site and is occupies the interstitial site, electrical neutrality as well as Stoichiometry of the compound are maintained this type of defect is called frenkel defect. It is also called dislocation defect.
Example:-
(AgCl, AgBr, AgI, ZnS) shows this defect which have a large difference in size of cations and anions.
Answer:
Defect or Imperfection:-
Any departure from perfectly ordered arrangement of the constituent particles in the crystal called imperfection or defect.
The defects in the crystal are arises when crystallization takes place at the fast or moderate rates because the constituent particles does not get sufficient time to arrange in perfect order.
There are mainly two types of defects:-
Point defect:-When the deviation or irregularities exists from ideal arrangement around a point or an atom in a crystalline substance the defect is called the point defect.
Line defect:- When the deviation from the ideal arrangement exists in the entire row of lattice points the defect is called as line defect.
Types of the point defects:-
1. Stoichiometric defects
2. Non stoichiometric defects
3. Impurity defects
Stoichiometric defect:-
If imperfection in the crystal are such that the ratio between cation and onions remains same. Stoichiometry of substance do not disturbed defect is called stoichiometric defect these defects are of the following types.
1. Vacancy defect:-
When is in a crystalline substance, some of the lattice sites are vacant the crystal is said to have vacancy defect it results in decrease of density of substance.
2. Interstitial defect:-
When some extra constituent particles are present in the interstitial site the crystal is said to be have interstitial defect.
This defect increases density of the crystal
These above types of defects are shown only by non – ionic solids.
3. Schottky defect:-
If in an ionic crystal of the type A+B- equal number of cations and anions are missing from the lattice site. So that electrical neutrality is remained is called schottky defect.
Compounds exhibiting schottky defect are NaCl, KCl
Which compounds have small difference in size of cation and anions show defect.
Frenkel defect:- If an ion is missing, from its lattice site and is occupies the interstitial site, electrical neutrality as well as Stoichiometry of the compound are maintained this type of defect is called frenkel defect. It is also called dislocation defect.
Example:-
(AgCl, AgBr, AgI, ZnS) shows this defect which have a large difference in size of cations and anions.
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