ON THE NATURE OF BORON-CARBON-NITROGEN COMPOUNDS SYNTHESIZED FROM ORGANIC PRECURSORS

Three compounds were prepared through pyrolysis of organic precursors. namely pyridine-borane, piperazine-borane, poly(acrylonitrile)-BCl3, following the routes proposed in the literature for the synthesis of single-phase boron carbonitrides of various compositions. X-ray diffraction and MAS NMR studies performed on the powders obtained suggest that the resulting compounds are mixtures of amorphous boron and turbostratically distorted hexagonal boron nitride and graphite rather than substitutional solid solutions of all three elements in a honeycomb network, as was claimed previously. Such a conclusion is also consistent with the results of the XRD investigation of the samples after subsequent heat treatment at 1800-2000 degrees C in argon and in nitrogen of atmospheric pressure.