A new view of Inner Core from recent synchrotron radiation studies: phase stability and primary pressure scale

There are several debated issues on the inner core. One of the debated issues is its crystal structure, whether it has the hcp-structure or bcc-structure. Another debated issue is the ambiguity of the pressure scale. There are inconsistencies among the pressure scales when we argue the inner core, since significant extrapolation and approximations are needed especially at pressures of the inner core. Here, Dr. Ohtani discusses these debated issues and shows the limitations of the present understanding of the inner core.