Transparent surface crystallized glasses consisting of ferroelectric stillwellite-type LaBGeO5 crystalline phase and showing second harmonic generation were successfully prepared. The crystallized glasses were fabricated through two-step heat-treatment in air (e.g. 670°C, 3 h + 750°C, 5 h) for 25La2O3 · 25B2O3 · 50GeO2 glass. The temperature of maximum nucleation rate was determined to be 670°C from differential thermal analyses, which is consistent with the glass transition temperature. The LaBGeO5 crystalline phase was confirmed to be formed at the surface region of about 60 μm and the grains were more oriented in the interior. The second harmonic intensity from the surface was in the order of 1/100 in comparison with that of quartz α-SiO2.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry