why is Fe0(s) not formed in stoichiometric compostion ?

Explanation

in the crystals of FeO some of the `Fe^(2+)` cations are replaced by `Fe^(3+)` ions three `fe^(2+)` ions are repllaced by two `Fe^(3+)` ion to make up the loss of positive chaarge Eventually three would be less amount of metal as comparition