|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Frontiers in Materials Science, Engineering, and Technology: An FMD Symposium in Honor of Sungho Jin
||Direct Conversion of h-BN into Phase Pure c-BN and Size Dependent Raman Spectroscopy of Nano and Micro Structures, and Thin Films of c-BN
||Ariful Haque, Anagh Bhaumik, Jagdish Narayan
|On-Site Speaker (Planned)
We discovered single step conversion of hexagonal boron nitride (h-BN) into phase pure cubic boron nitride (c-BN) by laser annealing technique. The h-BN thin films were deposited on c-sapphire substrate by pulsed laser deposition technique using pulsed KrF laser. An ArF nanosecond excimer laser was used for rapid melting and super undercooling and quenching to convert the h-BN into c-BN at ambient temperature and pressure. The diameter of the crystallite c-BN structures ranging from few nanometers to hundred micrometers can be controlled by varying the laser parameters. The Raman spectra of LO and TO modes of c-BN were found to be increasingly asymmetric, broader, and shifted towards lower wave numbers with decreasing crystal size. The structure determination and phase identification performed by electron back scattered diffraction (EBSD) technique in the c-BN nano crystals and large area thin films confirm high crystallinity and phase purity in this versatile material.
||Planned: Supplemental Proceedings volume