Pressure-driven conductivity of lizardite-implication to the high
conductive layers in craton lithosphere
Abstract
The electrical transport behavior of lizardite was investigated by
in-situ impedance measurements up to 22.6 GPa in a diamond anvil
cell with comparation to its dehydrated counterpart. The conductivity of
lizardite is found to increase one order of magnitude with increasing
pressures from 0.2 to 1.9 GPa, due to pressure-activated ionic and
electronic transportation. The proton hopping and hopping-created
vacancy accounts for the conduction mechanisms. Compression initially
promotes proton hopping at lower pressures and then impedes it at
elevates pressure to make conduction purely electronic. Compared to the
dehydrated specimen, the hydroxyl in lizardite enhances conductivity 4-7
times. The electronic resistivity at higher pressures gradually
increases at a constant rate, except in the pressure range where
pressure minimized the misfit structural disordering. The
pressure-activated proton hopping in the lizardite and other
phyllosilicates may ascribe the high conductive layer in the craton
lithosphere and geoelectric anomalies related to earthquakes.