On the electric properties of ice doped with NH4F

Levi, Laura; Lubart, Luisa; Gränicher, H.

doi:10.1007/bf02422781

Cited by 3 publications

(1 citation statement)

References 9 publications

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“…Taken together, these results seem to indicate (a) that ammonium fluoride fits into the ice lattice better than m ost other solutes, and (b ) that it generates fewer electrical point defects (ionic and orientational d efects) . The foregoing reconciles to some extent apparently conflicting m easurement results reported by Dengel and others (1966) and by Levi and Lubart ( 1968), r espectively.…”

Section: Discussionsupporting

confidence: 79%

Electrical Conductivity and Relaxation in Ice Crystals with Known Impurity Content

1978

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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...

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Section: Discussionsupporting

confidence: 79%

Electrical Conductivity and Relaxation in Ice Crystals with Known Impurity Content

1978

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Electrical Conductivity and Relaxation in Ice Crystals with Known Impurity Content

1978

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Three-terminal dielectric bridge measurements (in the range 20 Hz to 100 kHz between — 5°C and —90 to — 120°C) have been made of ice doped with (a) conductivity-enhancing ionic impurities (HCl, HF, NaCl, KF, NH4F) and (b) conductivity-depressing solutes (NH4OH, NH4Cl, NH5CO3, NaHCO3). Blocking electrodes were used for the first group. The true ice parameters were extracted from linearized plots of the Debye equations. Chlorides and fluorides showed very similar characteristics in their spectra and static conductivity. The results suggest that static conductivity is controlled by extrinsic protons. On the other hand, bases, or solutes that impart a positive freezing potential to the ice, suppress extrinsic protons. In this case, the static conductivity was not, or only weakly, temperature dependent and lower than in the first group. A conductivity cross-over was observed in neither case. The dielectric conductivity contribution is strongly dependent on impurity concentration but apparently less affected than the static conductivity 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.

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Loss-factor behavior of freshwater ice at 13.5 and 37.5 GHz

Bordonski¹,

Krylov²

1998

IEEE Trans. Geosci. Remote Sensing

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On the electric properties of ice doped with NH4F

Cited by 3 publications

References 9 publications

Electrical Conductivity and Relaxation in Ice Crystals with Known Impurity Content

Electrical Conductivity and Relaxation in Ice Crystals with Known Impurity Content

Electrical Conductivity and Relaxation in Ice Crystals with Known Impurity Content

Loss-factor behavior of freshwater ice at 13.5 and 37.5 GHz

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