Neutron Diffraction Study on the Kinetics of Non-Equilibrium Phase Transition in Ag3SI

Abstract

The kinetics of the ordering process in the first order phase transition of superionic Ag 3 SI was investigated by neutron diffraction. α-Ag 3 SI was quenched to certain temperatures of T c - Δ T , and the time dependence of integrated intensities and line widths of 111 reflection were measured for various Δ T from 20 K to 75 K. The time development scheme of the intensities can be categorized into three ranges of \(\varDelta T:\varDelta T{\lesssim}32\,\text{K}\), \(35\,\text{K}{\lesssim}\varDelta T{\lesssim}42\,\text{K}\) and \(55\text{K}{\lesssim}\varDelta T\). In the first range data show the initial stage of domain nucleation. Relaxation time τ was estimated from the intensity data. The values thus obtained for \(\varDelta T{\gtrsim}32\,\text{K}\) were not explained from the measurement of line widths, especially for \(\varDelta T{\lesssim}55\,\text{K}\), though the time dependence of line widths followed nearly to the t -1/2 behavior. As a matter of course the validity of a universal scaling property...