The Influence of the Rate of Deformation on the Electrical Properties of Ice Monocrystals

• Published in: Journal of Glaciology
• Main Author: Noll, G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1978
• Subjects: Earth-Surface Processes; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s0022143000033475; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000033475

Abstract The influence of plastic deformation on the electrical properties of ice monocrystals has been measured in the frequency range 10 -2 to 10 5 Hz as a function of strain-rate and strain. The crystals have been tested mainly under uniaxial compression, their orientation being for glide in the basal glide system (0001)[1120]. The resolved shear strain-rate ranged from 2 × 10 -5 to 1 × 10 -3 s -1 , the resolved shear strain from 3 to 60% u . Transient as well as bridge methods have been used for the electrical measurements before, during and after the deformation, Plastic deformation reduces the electrical conductivity in the space-charge dispersion range. The decrease depends strongly on the strain-rate; the size of the strain has practically no influence. After the end of the deformation recovery processes have been observed, which restored the original conductivity if the total strain was small. Rapid and large deformations however leave permanent changes. The changes of the d.c. conductivity and of the dispersion strength in the space-charge region are discussed and attributed to the increase of the dislocation density and the change of character of the dislocation network.