Compression rate-dependence of the <i>γ</i> → <i>α</i> phase boundary in cerium

Abstract

Rapid compression experiments were performed to examine the compression rate-dependence of the γ→α phase boundary in cerium (Ce), using a piezo-driven dynamic diamond anvil cell (dDAC) coupled with time-resolved ruby fluorescence (i.e., pressure profile) measurements. Accompanying the pressure-induced γ→α transition, large volume collapse in Ce leads to an obvious anomaly (i.e., plateau) in the pressure profile, which provides a unique opportunity for locating the phase boundary. Based on the pressure profile analysis, the transition pressures were determined over compression rates spanning three orders of magnitude (100--102 GPa/s). Unlike other metals that high compression rates can shift their phase boundaries to higher pressures, Ce shows little impact of the compression rate on its γ→α phase boundary. However, our observations are in good agreement with recent results obtained through dDAC combined with time-resolved synchrotron x-ray diffraction. This finding confirms the distinct compression rate-dependent phase transition behavior of Ce and highlights the possibility to capturing kinetic effects of phase transition up to hundreds of GPa/s in a home-built laboratory previously only accessible with large-scale x-ray source facilities.