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DOE OSTI · 1608856

Dynamic experiments to study the α - ε phase transition in cerium

Jensen, B. J.·Cherne, F. J.·Velisavljevic, N.
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Abstract

The ability to understand and predict the response of matter at extreme conditions requires knowledge of a material’s equation-of-state including the location of phase boundaries, transition kinetics, and the evolution of material strength. Cerium is a material with a complex phase diagram that continues to attract significant scientific interest. Recent dynamic experiments have provided information on the low-pressure γ–α phase transition, sound speed, and Hugoniot data for the higher-pressure α phase, as well as the incipient shock melt transition. Despite these efforts, there are still regions of the phase diagram that are largely unexplored dynamically, including the high-pressure region below the melt boundary. Along a room temperature isotherm, diamond anvil cell data report a transition to the ϵ phase between 13 and 17 GPa. At higher temperatures, similar diamond anvil cell data show significant disagreement regarding the existence, location, and slope of the ϵ-phase boundary. In this work, double-shock loading was used to access the α–ϵ region of the phase diagram to obtain equation-of-state information and to determine the location of the ϵ-phase boundary for shock loading.

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74 ATOMIC AND MOLECULAR PHYSICScomplex loadingdiamond anvil cellsdouble-shockequations of stateshock loadingsolid-solid phase transitionx-ray diffraction

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Jensen, B. J., Cherne, F. J., Velisavljevic, N.. 2020-03-07. Dynamic experiments to study the α - ε phase transition in cerium. https://doi.org/10.1063/1.5142508

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