Define Metal Deficiency Defects of Crystal - QS Study
QS Study

Metal Deficiency Defects: In certain cases, one of the positive ions is missing from its lattice site and the extra negative charge is balanced by some nearby metal ion acquiring additional charges instead of original charge. This type of defect is generally found in compounds of transition metals which can exhibit variable valency. FeO and FeS show this type of defects.

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