what are crystal lattice point defects? how many types are there?
Answers
Answer:
Point defects explain about the imperfections of solids along with the types of point defects. Crystalline solids are formed by joining many small crystals. Different types of defects are found in crystals after the process of crystallization.
Point defects are accounted for when the crystallization process occurs at a very fast rate. These defects mainly happen due to deviation in the arrangement of constituting particles. In a crystalline solid, when the ideal arrangement of solids is distorted around a point/ atom it is called a point defect.
Defects or Imperfections in crystalline solid can be divided into four groups namely line defects, point defects, volume defects and surface defects. Historically, crystal point defects were first regarded in ionic crystals, not in metal crystals that were much simpler.
There are 3 types of point defects:
Stoichiometric defect
Frenkel defect
Schottky defect
1. Stoichiometric Defect:
In this kind of point defect, the ratio of positive and negative ions (Stoichiometric) and electrical neutrality of a solid is not disturbed. Sometimes it is also known as intrinsic or thermodynamic defects.
Fundamentally, they are of two types:
Vacancy defect: When an atom is not present at their lattice sites, then that lattice site is vacant and it creates a vacancy defect. Due to this, the density of a substance decreases.
Interstitial defect: It is a defect in which an atom or molecule occupies the intermolecular spaces in crystals. In this defect, the density of the substance increases.
A non-ionic compound mainly shows vacancy and interstitial defects. An ionic compound shows the same in Frenkel and Schottky defect.
2. Frenkel Defect:
In ionic solids generally, the smaller ion (cation) moves out of its place and occupies an intermolecular space. In this case, a vacancy defect is created on its original position and the interstitial defect is experienced at its new position.
It is also known as dislocation defect.
The density of a substance remains unchanged.
It happens when there is a huge difference in the size of anions and cations.
Example: ZnS and AgCl
Explanation:
please mark me as a BRAINLIEST and be my follower I will help you again surely. keep following me:)