Brillouin scattering of glass-forming KCN:x mixture solutions within 0.58 < x < 0.64

Few investigations of glass transition in the glass-forming materials [KNO3]x[Ca(NO3)2](1−x) (KCN:x), except at x = 0.6 have been performed. The glass-forming range in KCN:x were obtained to be 0.58 < x < 0.64 from in situ observation using a stereoscope. For x < 0.58 and x > 0.64, crystal growth was observed. Brillouin scattering measurements in these mixture solutions, mainly for x values of the glass-forming region, have been performed as a function of temperature. From the thermal compressibilities β estimated by fitting analysis, their gradients from the glass transition temperature to about 170 °C (=Tcr) depend on x. This means that the ways of approaching the glass state from Tcr are slightly different in KCN:x. This Tcr is suggested to be a special temperature in the middle of the supercooling region during cooling and to specify the boundary from a liquid-like state to a solid-like state.