High-pressure-temperature phase diagram and the equation of state of beryllium

Article

关键词: X-RAY-DIFFRACTION;    GENERALIZED GRADIENT APPROXIMATION;    SINGLE-CRYSTAL;    SOLIDS;    SYSTEM;   

DOI  :  10.1103/PhysRevB.86.174118

来源: SCIE

【 摘 要 】

X-ray diffraction of beryllium in a laser-heated diamond anvil cell provides experimental insight into its behavior at high pressure and temperature. We measure the cold compression of Be in helium and NaCl pressure media up 192 GPa, and its thermal expansion up to 82 GPa and 2630 K. The new measurements form a P-V-T data set which is fit by the Vinet-Debye form to establish a Be experimental equation of state. We compare the results to several theoretical models. The crystal structure of Be is determined up to 205 GPa and 4000 K; no evidence for the predicted high-temperature transition to a cubic phase is found. Finally, the maximum temperature stability of the solid phase along isobaric heating ramps gives a lower bound for the melting curve.

【 授权许可】

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