SrO-GeO_2系のTTT(時間-温度-変態)図

TTT diagram is necessary in glass forming systems to understand various phenomena such as phase separation and crystallization in supercooled liquid. A hot-thermocouple technique to establish the TTT diagram of glass forming systems has been proposed, which enables heating, temperature measurement, DTA and observation the state of the sample. Some TTT diagrams in the SrO-GeO2 system have been determined by this method. In this system phase separation of nucleation-growth type was observed at high temperature in supercooled state. From the TTT diagram various cooling conditions can be determined for obtaining transparent glass and phase separated glasses of nucleation-growth, spinodal decomposition and crystallization types. It is concluded that the TTT diagram is important to develop “new glassy materials”.