i. Interstitial compounds are those which are formed when small atoms like H, C, N, B, etc., are trapped inside the crystal lattice of metals.
ii. Interstitial compounds have variable composition and are non-stoichiometric in nature.
eg. TiC, TiH1.73, Mn4N, Fe3H, VH0.56, ZrH1.92, etc.
iii. The chemical properties of interstitial compounds are similar to those of the parent transition metal.
iv. Interstitial compounds are well known for transition metals because defects are present in the crystal lattice of transition metals. Due to this, vacant spaces (interstices) are present in the lattice of transition metals which can be easily occupied by small atoms such as H, C, N and B.
