Difference Between Schottky and Frenkel Defect

What is Frenkel Defect?

When an atom or cation leaves its original location in the lattice structure to create a vacancy while occupying another interstitial position within the solid crystal, the Frenkel Defect is formed.

What is the Schottky defect?

When they are oppositely charged atoms leave their corresponding lattice sites, they generate a pair of vacancy defects known as the Schottky defect. The overall electrical neutrality of the crystal is retained since both catio and anion exit the lattice sites at the same time.

Difference  between Schottky defect and Frenkel defect:

  • The Schottky defect occurs in those ionic crystals where the difference in size between cation and anion is small, Frenkel defect typically occurs in those ionic crystals where their size of the anion is too high as opposed to that of the execution.
  • Schottky defects the atom permanently to leave the crystal, while the Frenkel defect atoms leave the original lattice site and occupy the interstitial position, so the atom resides within the solid crystal.
  • The Schottky defect occurs both cation and anion leave the solid crystal, while the Frenkel defect only the smaller ion leaves its original lattice site, whereas the anion remains in original lattice sites.
  • The Schottky defect has two atoms which is reduced from the crystal for each Schottky defect, while the number of atoms present in the crystal before and after the Frenkel defect remains the same.
  • The Schottky defect produces two vacancies, while the Frenkel defect creates one vacancy as well as a self interstitial defect.
  • Due to vacancy formation, the Schottky defect reduces the density of the solid, Density of the solid crystal before and after the Frenkel defect remains the same as no atom leaves the solid.
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