Explosive Instability of Water-Ammonium Ice

The explosive instability (Bridgman effect) was observed over a wide temperature range from 100 to 255 K in solid water-ammonia mixtures subjected to the strong uniaxial compression at high pressures. The explosive effects were observed only for the ammonia concentrations no higher than 6 wt %. The temperature dependences of explosion thresholds were found to be nontrivial for all studied ammonia concentrations in the mixtures. With lowering temperature in the range 100-265 K, the explosive behavior of a solid mixture gave way to the plastic behavior and then again to the explosive behavior. The second low-temperature explosive interval had two maxima and two minima. The minima arc assigned to the phase transitions either in the water matrix or in ammonium dihydrate. The concentration dependences of explosion thresholds are explained for all temperature intervals in terms of the percolation in elastic networks.