Liquid Phase Separation and Precipitation of α-AgI Nano-Crystallites from AgI-Ag₂O-B₂O₃ Melt

抄録

The dc electrical conductivity, σ_dc, was measured for liquid (AgI)_x–(Ag₂O)_y–(B₂O₃)_1−(x+y) (x=0.7–0.9; y=0.05–0.2) by using an ac impedance method in particular concern with the precipitation mechanism in the α-AgI precipitated glass, which was prepared by a rapid quenching technique due to a twin-roller apparatus. The temperature dependence of σ_dc exhibits two inflexion points. The existence of two liquid phase separation was confirmed by the electrical conductivity measurements with the use of specially designed cell. In addition, the X-ray diffraction and the SEM (Scanning Electron Microscope) experiments were performed for the rapidly quenched samples. The α-AgI precipitated glass was obtained by adopting the higher holding temperature even for the composition for which the β-AgI precipitated glass was prepared in the case of a lower holding one. These results indicate the role of two liquid phase separation on the preparation process of nano α-AgI crystallites in the glass matrix.