In situ observation of the crystallization of amorphous boron nitride at high pressures and temperatures

The formation processes of cubic boron nitride (cBN) from disordered turbostratic BN are observed in situ under high pressures and temperatures. It is found that cBN grows directly from an amorphous matrix and not from different BN polymorphs as previously proposed. Only during quench and pressure release do new structural phases occur.