ON THE NATURE OF ELECTRICAL-POLARIZATION OF MATERIALS CAUSED BY CRACKS - APPLICATION TO ICE ELECTROMAGNETIC EMISSION

A general problem of electrical polarization of conducting non-piezoelectric materials (metals, semiconductors and ionics) with static and growing cracks is considered. As a main approach we used calculations of charge carrier motion under the action of inhomogeneous elastic stresses existing around crack tips, using the deformation potential approximation. It is shown that a crack can generate a potential difference across itself of up to 1 V. We analyse the distribution of electrical fields in the space around stable and moving cracks. Comparison with recent experimental results on ice shows the significance of the mechanism.