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

Abstract

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 δ T. The 300-K bulk modulus of B 0 = 32.5(1) GPa and its first pressure derivative, B 0 ' = 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)×10-6 K-1 and b = 9.4(4)×10-9 K-2. The parameter describing simultaneous pressure and temperature impact on thermal expansion coefficient (and, therefore, volume) is δ T = 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.

Topics

• impedance spectroscopy
• resistivity
• x-ray diffraction
• Magnesium
• Magnesium
• thermal expansion
• bulk modulus