Question

Why interstitial compounds have higher melting points than transition metals

Answer 1

Interstitial compounds are those which are formed when small atoms like H, C or N are trapped inside the crystal lattices of metals. They are usually non stoichiometric and are neither typically ionic nor covalent.

These small atoms add to the increased melting and boiling points of the crystal, higher than those of pure metals. They are very hard, some borides approach diamond in hardness.