Some elements go cubic under pressure
DOI: 10.1063/1.2800085
In the August 2007 issue of Physics Today (page 24) a Physics Update item mentions recent work, by Dominik Legut and coworkers, proposing that the simple crystal structure of polonium arises from relativistic effects. The piece states that polonium is the only element with this structure. That is not true: For 20 years or more, the structure has been known to occur in phosphorus at pressures above 10 GPa, in calcium above 32 GPa, and in arsenic above 25 GPa. Since those elements are all much less heavy than polonium, it seems unlikely that relativistic effects can be sufficient to account for their simple cubic phases.
More about the Authors
Richard Nelmes. (r.j.nelmes@rl.ac.uk) University of Edinburgh, Edinburgh, UK .
