Table of Contents
Frenkel Defect
Frenkel Defect – Definition:
- A Frenkel defect is a type of defect that can occur in a crystal lattice. It is named after Russian physicist Lev Frenkel, who first described the phenomenon in 1922.
- A Frenkel defect occurs when an atom is displaced from its normal position in the lattice, and then becomes trapped there. This can happen when an impurity atom is introduced into a crystal, or when a crystal is subjected to a sudden change in temperature or pressure.
- The trapped atom can move around within the lattice, and can cause the crystal to become unstable. This can lead to the crystal breaking up, or to other defects forming in the lattice.
Formation of Frenkel Defect
- When a metal ion is missing an electron, it is called a “cation.” When an electron is added to a metal ion, it is called an “anion.” If these ions come together, they can form a “defect” in the metal’s crystal structure.
- One common type of defect is called a Frenkel defect. In a Frenkel defect, an anion and a cation trade places. This can happen when an anion and cation collide, or when an anion moves through a metal crystal.
- When a Frenkel defect forms, the metal’s crystal structure is disrupted. This can cause the metal to become brittle and to lose its electrical and thermal conductivity.
Occurrence of the Imperfections in Solid Crystals
In crystals, imperfections can occur due to a variety of reasons. One common reason is that the crystal may not have been grown perfectly in the first place. This may be due to the fact that the crystal was grown in an environment with impurities, or that it was subjected to a stress or force that caused it to deform. In addition, crystals may also contain imperfections due to defects in the atoms or molecules that make up the crystal. These defects may be the result of irregularities in the bonding between atoms, or of defects in the crystal structure. Finally, crystals may also contain impurities, which are atoms or molecules that are not part of the crystal structure.
Frenkel Defect Definition
A Frenkel defect is a type of defect in a crystal lattice in which an electron is displaced from its normal position.
Frenkel Defect Example
- A Frenkel defect is a type of crystal defect that results from the displacement of a electron from its normal position in the crystal lattice. In the simplest case, an electron is dislocated from a site in the crystal and becomes a free electron. This type of Frenkel defect is called a simple Frenkel defect.
- A more complicated type of Frenkel defect can occur when an electron is displaced from its site and becomes trapped on a nearby site. This type of Frenkel defect is called a complex Frenkel defect.
- The most common Frenkel defect is the simple Frenkel defect.
Reason of Frenkel Defect
The reason for Frenkel defect is that the ionic interaction between the metal and the anion is too strong. When the metal ions are in a lattice, they are held together by strong ionic interactions. These interactions are so strong that the metal ions cannot move very far from each other, even when there is a lot of space between them. This results in a very ordered lattice. When a metal ion is missing from the lattice, the ionic interactions between the remaining metal ions are too strong, and they cannot move very far from each other. This results in a defect in the lattice.
Calculation of Number of Frenkel Defects
The number of Frenkel defects can be calculated by using the following equation:
N = (A/V)
Where:
N = number of Frenkel defects
A = atomic radius
V = volume of crystal
Difference between Schottky and Frenkel Defects
The main difference between Schottky and Frenkel defects is that Schottky defects are caused by the interaction between a metal and a semiconductor, while Frenkel defects are caused by the interaction between a metal and a crystal. Schottky defects are more common in metals, while Frenkel defects are more common in semiconductors. Schottky defects are also more stable than Frenkel defects.
