Shock synthesis of ternary diamond-like phases in the B-C-N system

Nanodispersed powders of the ternary graphite-like phases BC1.28N and BC2.1 4N have been used along with mixtures of powders of turbostratic BN and C i n high-temperature shock compression followed by sharp quenching. The yield of diamond-like phases has attained 50% by volume. The excess of the graph ite-like phase has been removed by treatment with molten alkalis containing nitrates and then with concentrated HClO4. The shock and chemical treatmen ts alter the compositions of the diamond-like phases towards BCN in both of the BCxN specimens on account of the segregation of the excess carbon foll owed by the dissolution of it. Precision lattice-parameter measurements and line shape analysis indicate that the diamond-like phase is a BN - C subst itutional solid solution. Treatment of a mechanical mixture of the graphite -like phases of carbon min BN under the same p and T conditions led to the formation of a mixture of cubic boron nitride and diamond.