Figure 2.

(a) XRD patterns of YAS frit after heat treatment at 1650 °C. The controlled heat treatment resulted in the formation of glass-ceramics, which revealed a polycrystalline structure predominantly composed of a major phase of YAG (JCPDS card no:79–1891) [41] and minor phase of Y₂Si₂O₇ (JCPDS card no:42–0168) [41]. (b) SEM (BSE mode) image of typical YAS frit, revealing a dense microstructure. (c) EDS elemental mapping and elemental distribution of Y, Al, Si and O elements. This figure shows mainly light gray grains with two different morphologies, both large and small. Based on the EDS point analysis, the large grains were identified as the YAG phase and small grains as the Y₂Si₂O₇ phase. The dark gray phase was identified as the YAS amorphous (glass) phase.