The boron nitride (BN) and carbon structural systems are similar in many aspects and form analogue allotropes. Boron nitride exists mainly in two crystalline structures hexagonal BN (hBN) and cubic BN (cBN). Hexagonal BN is trigonally sp2 bonded structures which corresponds to graphite. Cubic BN is tetrahedrally sp3 bonded structures which is relevant to cubic diamond. Like carbon, BN also forms fullerenes and nanotubes. Such analogy in carbon and BN systems may also invoke the expectation of similar properties. The strong covalent bonds of cubic boron nitride with high ionicity results in structure with very close atomic packing; which gives rise to outstanding mechanical and thermal properties.
