What are non-stoichiometric defects?

The defects which disturb the stoichiometry of the compounds are called non-stoichiometric defects. These defects are either due to presence of excess metal ions or deficiency of metal ions. Complete step by step answer: There are mainly four different types of non-stoichiometric defects.

What is stoichiometric defect in solid?

Stoichiometric defects are intrinsic defects in which the ratio of cations to anions remains exactly the same as represented by the molecular formula. They are mainly of two types: Vacancy defects in which an atom is not present at its lattice sites causing that lattice site to be vacant and create a vacancy defect.

Which among the following are non-stoichiometric defect?

(D) Impurity defect. Hint: It shows a non-stoichiometric defect. Most of the non-stoichiometric defects are shown by the transition metals. However, they also include halides, hydrides, carbides and nitrides.

What is an example of non-stoichiometric compound?

Many metal oxides and sulfides have non-stoichiometric examples; for example, stoichiometric iron(II) oxide, which is rare, has the formula FeO, whereas the more common material is nonstoichiometric, with the formula Fe0.95O.

What are the two types of non-stoichiometric defects?

Non-Stoichiometric Defects

• Nonstoichiometric inorganic solids contain the constituent elements in a non-stoichiometric ratio due to defects in their crystal structures.
• These defects are of two types: (i) metal excess defect and (ii) metal deficiency defect.

Why FeO is non-stoichiometric?

In FeO , some Fe2+ ions are replaced by Fe3 ions i.e., 3Fe2+≡2Fe3+ to maintain electrical neutrality. Hence , due to metal deficiency , the compounds obtained are non-stoichiometric composition with formula Fe0.95O.

What do you mean by non-stoichiometric hydrides?

Non stoichiometric hydrides are formed by the reaction of Hydrogen molecules and d-block and f-block and do not follow law of constant proportions. The metal and hydrogen are combined in the fractional form. Non stoichiometric hydrides are chemical inorganic compounds and its physical state is solid.

What is the basic difference between Schottky & Frenkel defect?

Now we need to see the differences between the two defects….Complete answer:

Schottky defect	Frenkel defect
It occurs when the atoms are totally missing from the crystal lattice.	It occurs when the atoms are just displaced from their position to some voids or interstitial sites of the crystal lattice.