Characterization of BaTiO₃ crystals formed in aluminosilicate glasses and their laser patterning

Abstract

BaTiO 3 crystals synthesized through the crystallization of 40BaO40TiO 2 15SiO 2 5Al 2 O 3 glass were characterized from Raman scattering spectrum, second harmonic generation (SHG), and polarization measurements. The structure of BaTiO 3 nanocrystals (³70 nm) formed initially was suggested to be pseudo-cubic (small tetragonality), and perovskite-type ferroelectric BaTiO 3 crystals were formed in the heat-treatments at high temperatures of ³930°C. The lines consisting of BaTiO 3 crystals were patterned at the surface of CuO-doped glass by irradiations of continuous-wave Yb:YVO 4 lasers with a wavelength of 1080 nm. It was confirmed that BaTiO 3 being present in the laser-irradiated parts exhibits SHGs and, in particular, BaTiO 3 formed in the laser ablation region has a tetragonal structure and a Curie temperature of ³135°C.