Transformation of shock-compressed graphite to hexagonal diamond in nanoseconds.

ABSTRACT: The graphite-to-diamond transformation under shock compression has been of broad scientific interest since 1961. The formation of hexagonal diamond (HD) is of particular interest because it is expected to be harder than cubic diamond and due to its use in terrestrial sciences as a marker at meteorite impact sites. However, the formation of diamond having a fully hexagonal structure continues to be questioned and remains unresolved. Using real-time (nanosecond), in situ x-ray diffraction measurements, we show unequivocally that highly oriented pyrolytic graphite, shock-compressed along the c axis to 50 GPa, transforms to highly oriented elastically strained HD with the (100)_HD plane parallel to the graphite basal plane. These findings contradict recent molecular dynamics s

SUBMITTER: Turneaure SJ 

PROVIDER: S-EPMC5659656 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature