Superionic transition in ice

The possibility of the proton system in ice to change its configuration is determined by the existence of Bjerrum and ionic defects. In this paper the concentrations of ionic defects are studied as a function of temperature. It is shown that at enough high temperatures the proton system undergoes a first order phase transition into the state with high concentrations of ionic defects. This transition is analogous to the transitions is ordinary superionic conductors. The possibility of experimental observation of this transition is discussed.