Electrical Conductivity and Relaxation in Ice Crystals with Known Impurity Content

Abstract

ABSTRACT. Three-terminal dielectric bridge m easurem ents (in the range 20 Hz to 100 kHz between -5°C a nd -go to -120°C) have been made of ice doped with (a ) conductivity-enhancing ionic impurities (HCI, HF, NaCI, KF, NH.F) and (b ) conductivity-depressing solutes (NH.OH, NH.CI, NH s C0 3 , NaHC0 3 ) . Blocking electrodes were used for the first group. The true ice parameters were extracted from linearized plots of the D e bye equations. Chlorides and fluorid es showed very similar characteristics in their spectra and static conduc tivity. The results sugges t that static conductivity is controlled by extrinsic protons. On the other h and , bases, or solutes that impart a p ositive freezing potential to the ice, suppress extrinsic protons. In this case, the stati c conductivity was not, or only weakly, te mperat ure depe ndent and lower than in the first group. A conduc tivity cross-over was observed in neither case. The diel ectric conductivity contribution is strongly dependent o n impurity conce ntration but a ppare ntly less affected than the static con ductivity by the nature of the solute. The principal relaxation time is reduced by most solutes, exceptions are pure (bicarbonate-free) bases, sodium bicarbonate, and carbon dioxide. R EsuME. Conductiuitc et dispersion clectrigue de cristaux de glace dopis auec des impuretcs en concentration co/Inlle. Nous avons effectu e des mesures e lectriques a la m e thode du pont (d e 20 Hz a 100 kHz e ntre -5°C et -go, -120°C) dans le cas d e glace dopee avec: (a ) des impuretes ioniques augmentant la conductivite (HCl, HF, NaCI, KF, NH.F), et (b ) d es impuretes diminuant la conductivite (NH.OH, NH.Cl, NH 5 CO" NaH C0 3 ) . D es electrodes bloqua ntes ont ete utilisees d ans le premier cas. Les param etr es propres a la glace ont ete obtenus a partir des form es linearisees des equa tions de D e bye. L es chlorures e t Ies fluorures entrainent des caracteristiques tres semblables d a ns les spectres et la conductivite statique . L es resultats suggerent que la conductivite en courant continu est co ntrcMe par des protons extrinseques, c'est-a-dire introduits p a r les impuretes. Au contra ire, les hydroxydes et les sels qui conduisent la glace a presenter un potentiel positif lors de la congelation, supprime nt les protons extrinseques. Dans ce cas la conductivite en coura nt continu n'est pas, ou seul ement faiblement, d ep endante de la temperature; e1le est, e n outre bien plus faible que pour le premier groupe d 'impuretes. L e "cross-over" de conductivite n'a e te observe dans a ucun d es cas . La contribution dieIectrique a la conductivite depend fortement de la concentration en impuretes mais est beaucoup moins affecte par la nature des impuretes que la conduc ti v ite en courant continu. L e temps d e relaxation prin cipal est diminue par toutes les impure tes saufles hydrox ydes purs (sans CO 2 ), le bi carb o n ate de sod ium e t le dioxyde de carbo n e .ZUSAMMENFASSUNG . Elektrische L eitfiihigkeit IllId R elaxation in Eiskristallen mit bekanntem Gehalt a...

Dielectric properties of Jovian satellite ice analogs for subsurface radar exploration: A review

“…The dielectric behavior of HCl doped ice is quite similar to that of HF doped ice [ Gross et al, ] even if, at low temperatures (i.e., below the crossover temperature), the curves of σ s and σ ∞ are less separated than those of the HF doped ice [ Takei and Maeno , ]. The effect of Cl − in ice has also been studied using salts like NaCl [ Gross et al, ; Grimm et al, ], KCl [ Maeno , ], and CaCl 2 [ Grimm et al, ].…”

A Critical Review of the Low-Frequency Electrical Properties of Ice Sheets and Glaciers

“…1) between the low and high-frequency limits on laboratory-grown pure or doped ice, as reviewed, e.g., by Takei and Maeno (1997) and Petrenko and Whitworth (1999) and complemented recently by Rusiniak's (2004) investigation on pure ice. While the electrical behaviour of pure laboratory ice is usually different to that of glacier ice, doped, polycrystalline laboratory ice can be a useful analogue (Glen and Paren, 1975;Camplin et al, 1978;Gross et al, 1978Gross et al, , 1980Caranti and Illingworth, 1983;Takei and Maeno, 1984). Investigations of the full dispersion characteristics of glacier ice sampled in-situ are rare (e.g., Glen and Paren, 1975;Fitzgerald and Paren, 1975;Maeno and Nishimura, 1978).…”

Study of the Development of Positive Streamers Along an Ice Surface

“…The shifts in potential across the liquid-metal interfaces will build up an excess or deficit of electrons in the metal and H 3 O + ions close to the cathode or OHions close to the anode [38,39]. As already emphasized in the section 2.2, when an aqueous solution is frozen, the chemical impurities are not necessarily incorporated in the proportion originally present in the solute [10,22,40]. In the case of sodium chloride solution (NaCl), which used to build the ice in this present works, the Clenters the ice leaving Na + and OHin the liquid phase [22,38].…”