Abstract
The α → β transformation behavior and the temperature dependence of lattice strain of α‐AgI crystal frozen in an AgI‐based orthoborate glass matrix were investigated by differential scanning calorimetry and x‐ray diffraction in the temperature range from 20 to 180°C. After heating to various temperatures, the glass matrix strongly suppressed the α → β transformation during cooling. The α → β transformation temperatures decreased with decreasing maximum heating, temperatures. The α‐AgI crystal frozen in the orthoborate glass matrix could not transform during cooling if the maximum heating temperature was lower than the glass transition temperature (Tg) of the matrix glass. The suppressing effect of α → β transformation of the glass matrix was suggested to become stronger with decreasing maximum heating temperature. The heterogeneous lattice strain of frozen α‐AgI was large when the composite was kept at temperatures below Tg, and became smaller at temperatures above Tg in the heating process. The α → β transformation occurred only during cooling after the lattice strain of α‐AgI was sufficiently released by heating to temperatures above Tg of the matrix glass. The large lattice strain of frozen α‐AgI and the value of Tg mainly affected the transformation behavior of α‐AgI in the glass matrix.