Difference between Metal excess defect and metal deficient defects

Difference between Metal excess and metal deficient defects

Difference between Metal excess defect and metal deficient defects are in tabular form below.

 Metal excess Defect

Metal deficiency defect

1)  A metal excess defect is a type of crystal defect that occurs in crystal lattices. Either an anionic vacancy or an extra Cation cause these defects. Metal Deficiency Defects is a type of crystal defect that occurs in crystal lattices in which either a cation vacancy or an extra anion causes the defects.
2) Metal Excess defects is caused by the anionic vacancies and by extra cation in the interstitial sites. Metal deficiency defects are caused by the cationic vacancies and by the extra anion in the interstitial sites.
3) Metal excess defect is when the anion escapes from the lattice and forms a bond with atmospheric cation. Metal deficiency defects arise when cation itself is surrounded by a sea of anion.
4) Examples: Cl- forming bonds in the atmosphere where Na+ is present this causes an electron to be shifted to the centre and all metal surrounded to the electron. Example: in Feo there is a tendency of Fe2+ to change to Fe3+ due to oxidation so in order for this to happens, some of this positive charge is lost, hence, metal is deficient
5) There are two different types of metal excess defects that are metal excess defects due to anionic vacancy and metal excess defect due to extra cations. These are two different type of metal deficiency defects that is that is metal deficiency defect due to presence of extra cations.
6) Metal defect Due to anionic vacancy the loss of negative ions from the lattice sites, which leave behind a hole that is occupied by an electron in order to maintain the electric balance of the crystal lattice. Metal deficiency defects due cation varancies, a cation is missing from its lattice site therefore, the extra negative charged is balanced by getting two charged insted of one charged.
7) These cations tend to occupy the interstitial sides of the crystal lattice, along with the cation formation the released electrons go to the neighboring interstitial sites.

 

Metal deficiency defects due to presence of extra cation.
8)  Examples: of a metal excess defect are sodium chloride, potassium chloride, zinc oxide etc. Extra anions occur on the interstitial sites and the adjacent ion at another interstitial sites help to maintain the electrical neurallity of the lattice.Example: Of a metal deficiency defect is nickel oxide.

Updated: November 25, 2021 — 5:03 pm

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