Liquid Carbon, Glassy Carbon, and Their Surfaces
[Technical Report, Final Report]
University of California - Berkeley
Pagination or Media Count:
We seek to advance our fundamental understanding of the liquid state and the phase diagram of carbon by performing detailed nonlinear optical electronic and vibrational spectroscopy studies of both the bulk and the surface of liquid carbon, and to exploit our novel laser technology to explore the nature of the newly-discovered Q-carbon form. The liquid will be prepared by non-thermal melting of graphite targets with both femtosecond and nanosecond lasers. The vibrational and electronic structures of the bulk liquid will be probed as a function of delay time from the melting pulse and thus as a function of temperature and pressure with our recently developed chirped femtosecond coherent anti-Stokes Raman spectroscopy c-CARS technique. Our new broadband deep-UV electronic sum frequency generation DUV-ESFG spectroscopy technique will be used to probe the surfaces. Our Single Photon InfraRed Emission Spectroscopy SPIRES spectrometer will be used to monitor the evolution of the super-undercooled liquid carbon into the Q-carbon stages. This collection of experiments, interpreted with state of the art theoretical calculations performed in collaboration with Berkeley-area theorists, will characterize the structure, bonding, and dynamics of liquid carbon, Q-carbon, and the various diamond structures needles, nanomicrodiamonds, ... nucleated from Q-carbon. Time resolved experiments will address the nucleation mechanisms of carbon nanotubes and diamond structures from the liquid and Q-carbon forms. Addition of dopantse.g. N, B to the diamond nanomicro-structures will be explored. The combined theoretical and experimental information obtained will ultimately be used to construct improved potential models that can describe all known phases and properties of carbon.
- Inorganic Chemistry
- Atomic and Molecular Physics and Spectroscopy