A Direct Comparison between Static and Dynamic Melting Temperature Determinations below 100GPa

A preliminary experiment of sound velocity measurements for porous iron with initial average density of 6.275g/cm³ has been performed at pressures below 100GPa, in order to clarify a long-standing problem that the static melting temperature Tm, mostly below 100GPa due to its technical limitations, is notably lower than the extrapolated melting data inferred from the shock wave experiments made above 200GPa, for the sake of making a direct comparison between the experimental static and dynamic melting temperatures in the same pressure region. With the lately proposed Hugoniot sound velocity data analysis technique Chin. Phys. Lett. 22 (2005) 863, the results deduced from this Hugoniot sound velocity measurement is T_m=3200K at 87GPa and T_m=3080K at 80GPa, which are in good agreement with the two latest static data of T_m=3510K at 105GPa and T_m=2750K at 58GPa, which utilized modern improved double-side laser heating and in situ accurate x-ray diffraction techniques in experiments. It can be concluded that consensus Tm data would be obtained from static and shock wave experiments in the case that the recently improved techniques are adopted in investigations.