Dense B-N Compounds: Synthesis Conditions and Physical Properties

The hexagonal form of boron nitride, isostructural to graphite, transforms to a three-dimensional network with the wurtzite structure upon the application of high pressure at room temperature. In its wurtzite phase, boron nitride exhibits a very low compressibility. Upon decompression, the wurtzite phase can be partially retrieved. In the study we have measured the physical properties wurtzitic boron nitride and the fraction of high-density phase retrievable from the initial bulk and nanoscale hexagonal boron nitride, as obtained from compression under various hydrostatic conditions and high temperature. The interaction and bonding formation at high density between boron nitride and different pressure transmitting media leading to the possibility of formation of dense intercalated compounds is also examined.