A comparative study of crystallization kinetics between conventionally melt quenched and mechanochemically synthesized AgI-Ag2O-CrO3 superionic system

Non-isothermal crystallization kinetics in conventionally melt quenched versus mechanochemically synthesized amorphous AgI-Ag2O-CrO3 superionic solids is discussed. The quenched as well as ball-milled samples exhibit glass (Tg) and multiple amorphous→crystalline (Tc) transitions. Tg as well as Tc are found to increase monotonically with heating rate. The activation energy for structural relaxation (Es) obtained using Moynihan equation is found to be higher for ball-milled samples that eventually suggests the relatively rigid and highly viscous structure of milled samples. The activation energy associated with nucleation and growth (Ec) is obtained using Matusita-Sakka equation and its higher value confirms the higher rate of crystallization in ball-milled samples. The values of Tc-Tg and the enthalpy of phase transformation (ΔH) are also found higher for the ball-milled samples that confirm their comparatively high thermal stability. The electrical conductivity near the crystallization temperatures is studied as a function of time and temperature and these results confirm the presence of amorphous → crystalline transition temperatures in the ball-milled as well as in the melt-quenched samples