Effect of Pressure on the Dielectric Properties of Ice Ih Single Crystals Doped with NH3 and HF

Abstract This paper describes measurements of the dielectric constant and of the conductivity on pure and doped ice single crystals subjected to hydrostatic pressure. The dopants used were NH3 (c NH3 ≈ 5 × 10-5 to 1.2 × 10-4 mol/1) or HF (c HF = 5 × 10-6 and 5 × 10-4 mol/1). The pressure and temperature ranges covered were 1 to 1 500 bar and — 15 to 60°C. The activation volumes for the orientational and the ionic contribution to the conductivity could be determined. A definitive interpretation is not possible because many questions concerning the formation of the defects are still open, hi addition to the main subject, some new data from conductivity measurements on NH3-doped single crystals at atmospheric pressure are presented.