X-ray diffraction study of elemental erbium to 70 GPa

We have investigated phase transitions in elemental erbium in a diamond anvil cell (DAC) up to 70 GPa using angular-dispersive x-ray powder diffraction methods. We present evidence of a series of phase transitions that appear to follow the anticipated hcp -> Sm-type -> double hcp (dhcp)-> distorted fcc sequence. In particular, we present evidence for the predicted dhcp -> distorted fcc transition above 63 GPa. Equation of state data are also presented up to 70 GPa.