Orientational Defects in Ice Ih: An Interpretation of Electrical Conductivity Measurements

TL;DR

This study uses first-principles calculations to analyze the structure and energetics of Bjerrum defects in ice Ih, providing insights into electrical conductivity and the role of traps versus free defect migration.

Contribution

It offers a detailed first-principles analysis of Bjerrum defects in ice Ih and compares the results with experimental electrical conductivity data, revealing new insights into defect energetics.

Findings

DFT activation energy matches experimental data

Different components contribute to activation energy

Traps may influence defect activity in doped ice

Abstract

We present a first-principles study of the structure and energetics of Bjerrum defects in ice Ih and compare the results to experimental electrical conductivity data. While the DFT result for the activation energy is in good agreement with experiment, we find that its two components have quite different values. Aside from providing new insight into the fundamental parameters of the microscopic electrical theory of ice, our results suggest the activity of traps in doped ice in the temperature regime typically assumed to be controlled by the free migration of L defects.