In situ electrical conductivity measurement of high-pressure molten (Mg0.875,Fe0.125)2SiO4

In situ resistance measurement of mantle mineral under high temperature and pressure has been considered an important method for studying the electrical properties and thermal states of Earth's interior. Here the authors report the results of the electrical conductivity of molten olivine [(Mg-0.875,Fe-0.125)(2)SiO4] on diamond anvil cell with pressure at 13.2 GPa and temperature at 3720 K. The results indicate that the activation enthalpy of molten olivine is much less than that of solid, and its conductivity is relatively insensitive to temperature. Moreover, at the given temperature range the conductivity of molten olivine exhibits Arrhenius behavior perfectly. Compared to the results of Hawaiian tholeiite provided by Tyburczy and Waff [J. Geophys. Res. 88, 1413 (1983)] at lower pressure and temperature, the pressure effect on molten olivine conductivity is slightly weaker. This method for electrical conductivity measurement on laser-heated diamond anvil cell allows the environment simulation study of unresearched regions of Earth, no longer restricted to large cavity press. (c) 2007 American Institute of Physics.