Kinetics of the cubic-to-hexagonal phase transformation in ice doped with Mossbauer ions

The transformation of cubic to hexagonal ice has been studied by measuring the time dependence of the dependence of the disappearance and reappearance of the Mossbauer effect in frozen aqueous solutions containing ferrous, ferric and europic ions. The rate of transformation is significantly decreased, compared to pure ice, and depends strongly on the identity and concentration of the trapped ions. Our observations indicate that the transformation occurs in at least two stages, with an intermediate state which can persist for extended time periods. and during which no Mossbauer resonance could be detected.