Electrical conductivity of ice VII
نویسندگان
چکیده
It was discovered that a peak appears near a pressure of Pc = 10 GPa in the electrical conductivity of ice VII as measured through impedance spectroscopy in a diamond anvil cell (DAC) during the process of compression from 2 GPa to 40 GPa at room temperature. The activation energy for the conductivity measured in the cooling/heating process between 278 K and 303 K reached a minimum near Pc. Theoretical modelling and molecular dynamics simulations suggest that the origin of this unique peak is the transition of the major charge carriers from the rotational defects to the ionic defects.
منابع مشابه
Tunable electrical and thermal transport in ice-templated multilayer graphene nanocomposites through freezing rate control.
We demonstrate tunable electrical and thermal conductivities through freezing rate control in solution-based nanocomposites. For a prototypical suspension of 1 vol % multilayer graphene suspended in hexadecane, the solid-liquid electrical conductivity contrast ratio can be tuned from 1 to 4.5 orders of magnitude for freezing rates between 10(2) and 10(-3) °C/min. We hypothesize that this dramat...
متن کاملThe role of acids in electrical conduction through ice
[1] Electrical conduction through meteoric polar ice is controlled by soluble impurities that originate mostly from sea salt, biomass burning, and volcanic eruptions. The strongest conductivity response is to acids, yet the mechanism causing this response has been unclear. Here we elucidate conduction mechanisms in ice using broadband dielectric spectroscopy of meteoric polar ice cores. We find...
متن کاملLow-frequency electrical properties of ice-silicate mixtures.
The low-frequency electrical properties of mixtures of silicates and saline H(2)O were measured over broad ranges of temperature and frequency to assess the subfreezing interactions between these materials synoptically, particularly the effects of adsorbed, unfrozen water. Adsorbed water content was determined using nuclear magnetic resonance. Materials were chosen to control effects of grain s...
متن کاملInstruments and Methods Improved method to determine radio-echo sounding reflector depths from ice-core profiles of permittivity and conductivity
We present a technique that modifies and extends down-hole target methods to provide absolute measures of uncertainty in radar-reflector depth of origin. We use ice-core profiles to model wave propagation and reflection, and then cross-correlate the model results with radio-echo sounding (RES) data to identify the depth of reflector events. Stacked traces recorded with RES near the EPICA drill ...
متن کاملSuppression of X-ray-induced dissociation of H2O molecules in dense ice under pressure
We investigated molecular dissociation induced by 10-keV X-ray irradiation in dense ice at pressures up to 40 GPa at 300 K. The dissociation yield estimated from the oxygen K-edge X-ray Raman spectra, showed that the molecular dissociation was enhanced up to 14 GPa and gradually suppressed on further compression to 40 GPa. The molecular dissociation was detected for a rather narrow pressure spa...
متن کامل