Lattice Parameters of Boron Nitride Polymorphous Modifications as a Function of Their Crystal-Structure Perfection

The data available in the literature on the lattice parameters of boron nitride (BN) polymorphic modifications have been analysed. A precise measurement of interplanar spacing has been carried out for hexagonal BN of different degrees of crystalline perfection and rhombohedral BN. The possibilities for alteration of wurtzitic BN lattice parameters have been studied. The results obtained have been used to establish the fundamental reference values of lattice parameters for all crystalline modifications of BN.