  Previous x-ray diffraction studies have reported Eu to transform from the hcp
structure to a new phase, Eu-III, at 18 GPa. Using x-ray powder diffraction we
have determined that Eu remains hcp up to 33 GPa, and that the extra peaks that
appear at 18 GPa are from an impurity phase with space group R-3c . Above 33
GPa the diffraction pattern becomes very much more complex, signalling a
transition to a phase with a distorted hcp structure.
