What is Frenkel defect What are conditions for its formation? A Frenkel defect is a type of point defect in crystalline solids, named after its discoverer Yakov Frenkel. The defect forms when an atom or smaller ion (usually cation) leaves its place in the lattice, creating a vacancy and becomes an interstitial by lodging in a nearby location.
What is Schottky and Frenkel defect?
Schottky defect occurs in those ionic crystals where the difference in size between cation and anion is small. Frenkel defect usually occurs in those ionic crystals where size of anion is quite large as compared to that of the cation. In Schottky defect, both cation and anion leave the solid crystal.
What is meant by Frenkel defect Mcq?
ANSWER: defect in which interstitial position is occupied by missing atoms.
Which one of the following is Frenkel defect?
So, from the above information we can conclude that silver bromide shows Frenkel defect.
What is the effect of defect on the density of ionic solids?
Because of the Frenkel defect, the density of ionic solids does not change. The Frenkel defect does not have any impact on the density of the solid as it involves the migration of the ions along with the crystal, hence having both the volume as well as mass. Hence, Option C is correct.
Related question for What Is Frenkel Defect What Are Conditions For Its Formation?
Why Frenkel defect is also known as dislocation defect?
Frenkel defects is the defect in which one of the ions leaves its lattice position and moves into an interstitial void, creating a vacancy at the lattice point. Since the ion is dislocated from its lattice site, the Frenkel defect is also known as dislocation defect.
Which of the following is a Frenkel defect Mcq?
Point Defect MCQ Question 7 Detailed Solution
As a result, the atom or ion leaves its own lattice site vacant. Thus, One Zn vacancy and one Zn interstitial in ZnO is a Frenkel defect.
What is Frenkel defect give an example class 12?
Frenkel defects are mostly exhibited in ionic solids where the smaller ion (usually the cation) is dislocated. Some examples include AgBr, ZnS, AgCl, and AgI. Here the defect occurs mainly due to the smaller size of Zn2+ and Ag+ ions.
What is meant by the point defect explain in brief?
Point defects are lattice defects of zero dimensionality, i.e., they do not possess lattice structure in any dimension. Typical point defects are impurity atoms in a pure metal, vacancies and self-interstitials.
What is the cause of defect in crystals?
crystal defect, imperfection in the regular geometrical arrangement of the atoms in a crystalline solid. These imperfections result from deformation of the solid, rapid cooling from high temperature, or high-energy radiation (X-rays or neutrons) striking the solid.
In which of the following defects the density of the crystal is affected?
Schottky defects-This defect is due to vacancy at a cation site accomparied by vacancy at an anion site so that the electrical neutrality of the system is maintained. Due to this defect, density decreases.
Which of the following does not exhibit Frenkel defect?
KBr exhibits Schottky defect and not Frenkel defect.
Which defect is also known as dislocation defect?
(a) Frenkel defect is also known as dislocation defect because in Frenkel defect atoms present in the crystal lattice is dislocated to an interstitial site.
Which of the following is not characteristic of Frenkel defect?
In pure alkali halides, Frenkel defects are not found since the big alkali metal ions cannot get into the interstital sites, Frenkel defects are found in silver halides beacause of the small size of the Ag+ ion. In certain ionic solids such as AgBr both Schottky and Frenkel defeat occur.
What is its effect on the density of solid?
When a substance is heated its volume increases and so the density decreases. In solids, increase in volume is negligible and hence decrease in density too. In liquids and gases, as the temperature increases, volume increases and therefore density decreases considerably.
What is the effect of vacancy defect on the density of the substance *?
Vacancy defect results in a decrease in the density of the substance.
Which of the following defect does not change the density of solids?
Due to Frenkel defect there is no effect on density of a solid.
When Frenkel defect occurs in a crystal density?
Thus, it can be said that Frenkel defects are shown by those ionic solids which have large size differences between the cation and anion. Frenkel defect doesn't have any impact on density, mass or volume of the crystal as in this defect migration of ions takes place within the crystal.
What are Schottky and Frenkel defects How does density of a solid get affected by these defects?
One Frenkel defect creates one vacancy and one self-interstitial defect. The number of atoms present in the crystal before and after Frenkel defect remains same. Density of the solid crystal before and after Frenkel defect remains same as no atom leaves the solid.
How does density and conductivity changes in Frenkel defect?
What is the effect of Frenkel defect on electrical conductivity of the solid? Compounds having frenkel defect conduct electricity to a small extent. When electric field is applied, an ion moves from its lattice site to occupy a hole, it creates a new hole. Thus, it conducts electricity across the crystal.
How do Schottky and Frenkel defect increases the conductivity of a crystal?
In Schottky defect: equal number of cation and anions are missing from their normal lattice sites. i.e. equal cationic and anionic vacancies will be developed. Due to the vacancies, movement of electron become easy which allow crystal to show more electrical conductivity.
What type of crystal defect affect electrical conduction of solids?
Point defects are common in crystals with large anions such as AgBr, AgI, RbAgI4. Due to the defects, the ions have some freedom to move about in crystals, making them relatively good conductors. These are called ionic conductors, unlike metals in which electrons are responsible for electric conductivity.
Which type of defect is present in brass explain Frenkel defect?
1) When cation or anion from ionic solid leaves its regular site and moves to occupy a place between the lattice site called interstitial position, the defect is called interstitial defect or Frenkel defect. 2)The presence of this defect does not alter the density of the solid.