Highly ordered graphite (HOPG) to hexagonal diamond (lonsdaleite) phase transition observed on picosecond time scales using ultrafast x-ray diffraction
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); SLAC
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- University of Nevada, Las Vegas, NV (United States)
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Carnegie Institute of Science, Washington, DC (United States)
- University of Potsdam (Germany)
- Argonne National Lab. (ANL), Argonne, IL (United States)
- University of Freiburg (Germany)
- Stanford University, CA (United States)
Here, the response of rapidly compressed highly oriented pyrolytic graphite (HOPG) normal to its basal plane was investigated at a pressure of ~80 GPa. Ultrafast x-ray diffraction using ~100 fs pulses at the Materials Under Extreme Conditions sector of the Linac Coherent Light Source was used to probe the changes in crystal structure resulting from picosecond timescale compression at laser drive energies ranging from 2.5 to 250 mJ. A phase transformation from HOPG to a highly textured hexagonal diamond structure is observed at the highest energy, followed by relaxation to a still highly oriented, but distorted graphite structure following release. We observe the formation of a highly oriented lonsdaleite within 20 ps, subsequent to compression. This suggests that a diffusionless martensitic mechanism may play a fundamental role in phase transition, as speculated in an early work on this system, and more recent static studies of diamonds formed in impact events.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
- Sponsoring Organization:
- Carnegie Institution of Washington; Defense Threat Reduction Agency (DTRA); National Science Foundation (NSF); US Army Research Office (ARO); USDOE; USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Fusion Energy Sciences (FES)
- Grant/Contract Number:
- AC02-76SF00515; AC52-07NA27344; FG02-94ER14466
- OSTI ID:
- 1886935
- Report Number(s):
- LLNL-JRNL-822386
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 132; ISSN 0021-8979
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Nanosecond formation of diamond and lonsdaleite by shock compression of graphite
Transformation of shock-compressed graphite to hexagonal diamond in nanoseconds
Related Subjects
Physics - Solid state physics
Materials science
Physics - Condensed matter physics
Chemistry
carbon based materials
chemistry
condensed matter physics
crystal structure
diamond
hydrodynamics simulations
lasers
phase transitions
shock compression
shock waves
solid state physics
ultrafast x-ray diffraction
wave mechanics