Фазовое превращение сBN→hBN под высоким давлением при комнатной температуре в порошках кубического нитрида бора, содержащих фракции нанодиапазона

Abstract

Phase transitions in cubic boron nitride at high pressure and ambient temperature investigated by X-ray analysis method in two ways. According to the first way XRD spectrums obtained from samples after operation of pressing in the device of high pressure with сemented carbide anvils. According to the second way XRD spectrums obtained «in situ» from samples under loading in the shear diamond anvil cell (SDAC) and transparent of X-ray. Objects of research were сBN powders, containing different quantity of fractions in the nano range. It is shown, that the powder of cubic boron nitride with particle size in the nano range shows the behavior different from a massive material. Influence of high pressure at ambient temperature initiates сBN→hBN phase transition. At unloading this phase transition happens as reversable in full or in part.