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arXiv 1909.00645cond-mat.mtrl-sci
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高温高压下金属镁的热弹性状态方程与熔化

Thermoelastic equation of state and melting of Mg metal at high pressure and high temperature

Alexandre Courac, Yann Le Godec, Vladimir L. Solozhenko, Nicolas Guignot, Wilson A. Crichton

摘要:

用多对顶和对顶技术结合同步辐射X射线衍射测量了金属镁在20 GPa和1500 K下的p-V-T状态方程。为了拟合实验数据,使用了Anderson-Grüneisen模型,其中固定参数δT。用Murnaghan状态方程拟合了20 GPa以下的实验数据,得到了300 K时的体积模量B 0 = 32.5(1)GPa,压力导数B 0 ' = 3.73(2)。环境压力下的热膨胀已使用系数a = 25(2)x10-6 K-1和b = 9.4(4)x10-9 K-2的二阶多项式描述。描述压力和温度同时影响热膨胀系数(以及体积)的参数为δT = 1.5(5)。拟合的和实验的等压线之间的良好的协议已达到相对体积为0.75。通过X射线衍射和原位电阻率测量观察到的Mg熔化证实了先前的结果,并且另外证实了熔化附近的p-T估计。

英文摘要:

The p-V-T equation of state of magnesium metal has been measured up to 20 GPa and 1500 K using both multianvil and opposite anvil techniques combined with synchrotron X-ray diffraction. To fit the experimental data, the model of Anderson-Grüneisen has been used with fixed parameter δT. The 300-K bulk modulus of B0 = 32.5(1) GPa and its first pressure derivative, B0' = 3.73(2), have been obtained by fitting available data up to 20 GPa to Murnaghan equation of state. Thermal expansion at ambient pressure has been described using second order polynomial with coefficients a = 25(2)x10-6 K-1 and b = 9.4(4)x10-9 K-2. The parameter describing simultaneous pressure and temperature impact on thermal expansion coefficient (and, therefore, volume) is δT = 1.5(5). The good agreement between fitted and experimental isobars has been achieved to relative volumes of 0.75. The Mg melting observed by X-ray diffraction and in situ electrical resistivity measurements confirms previous results and additionally confirms the p-T estimations in the vicinity of melting.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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