B, B-C and B-N compounds at high pressures and hig temperatures

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The overall scientific goals of the project are: (1) to investigate the stability field of the new HPHT boron in ´in situ´ high-pressure high-temperature experiments; (2) to synthesize new HPHT boron-carbon and boron-nitrogen compounds using diamond anvil cells and a large-volume multi-anvil apparatus; (3) to study their physical-chemical, structural, elastic and bonding properties, equations of state and thermal stability, as well as electrical and electronic properties; and (4) , to verify relevant theoretical predictions on structural changes associated with the increase of C or N component in these compounds. In the proposed research, the formation of new phases in the B–C and B-N systems will be systematically examined over wide pressure and temperature ranges using a laser heated diamond anvil cell (up to 50 GPa and 3000 K), a large-volume high P–T apparatus (up to 25 GPa and 2500 K) and X-ray diffraction with in house and synchrotron radiation, as well as Raman spectroscopy. The structure and properties of quenched samples will be analyzed by powder X-ray diffraction, Raman spectroscopy, electron microscopy, electron energy loss spectroscopy, hardness measurements, and electrical transport properties measurements.