1. Lee Davison and R. A. Graham, Phys. Reports, 55, 257 (1979).
2. D. R. Curran, J. Appl. Phys 36, 2591 (1965).
3. R. A. Graham and J. R. Asay, High Temp.-High Press., 10, 355 (1978).
4. Samples were provided by W. J. Nellis, LLNL, Livermore, CA.
5. J. L. Wise, Sandia National Laboratories, private communication.