Dielectric relaxation spectrum of ice measured with linear blocking layers

Abstract

A systematic study of the dielectric relaxation spectrum of ionic impurities in ice over a wide range of concentrations and temperatures required the development of methods to compare the spectra. The studied impurities fall roughly into two categories, those that increase the dc conductivity of the ice and attendant space‐charge effects, and those that suppress these effects. The former were measured with blocking layers inserted between the sample and electrodes, the latter with stainless steel guard electrodes. Linearized plots of the Debye expressions were used for separating up to 4 spectral components by an iterative fitting and correction technique. With blocking layers, the Maxwell‐Wagner model of a layered dielectric yields the ice bulk parameters. Analysis suggests that, in general, ice is best described by a small number of discrete components, each characterized by a single relaxation time. Advantages of the blocking‐layer technique are experimental simplicity, reproducible values of electrical parameters obtained exclusively from ac measurements, and the systematic coverage possible. The results are useful for evaluating electrical properties of ice in the environment. The model should be applicable to the investigation of rocks other than ice.

Dielectric Behaviour of Firn and Ice from the Antarctic Peninsula, Antarctica

“…of nine samples from the Antarctic Peninsula have been l compared in Figure 5 with values of am. for doped ice samples studied by 1 Camplin and others (1978), and by Gross and others (1980). The Antarctic Peninsula data match the trends of the published a CD • values for HF-and HCl-doped ice remarkably well.…”

Precise dielectric profiling of ice cores: a new device with improved guarding and its theory

“…When an ice sample contacts a metal electrode, the ice and metal partially exchange charges (Petrenko, 1993). This exchange can be eliminated by inserting an insulating blocking layer between the sample and the electrodes (Mounier and Sixou, 1969; Gross and others, 1975), for example a thin film of Teflon (Gross and others, 1980). Alternatively, in a modern DEP instrument, the blocking layer is achieved by anodizing the aluminum electrodes (Wolff and others, 1995).…”

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).…”