| 초록 |
A spherical Sm3+ doped Ba2TiSi2O8 glasses were prepared by aerodynamic levitation. In order to fabricate nanocrystallized BTS glass with excellent optical properties, optimal conditions of heat-treatment were investigated and the effects of heat-treatment temperature on the microstructure and photoluminescence characteristics were also investigated carefully. For comparisons, the Sm3+ doped BTS glasses were also prepared by conventional melt-quenching process. From the DSC and XRD analyses, the glass prepared by aerodynamic levitation represented enhanced thermal stability. With increasing the heat treatment temperature, the lattice parameter, a of nanocrystalline BTS crystal formed in glass decreased, but the lattice parameter, c of that increased. This result is reasonable considering that the residual stresses occurred during cooling due to difference of linear thermal expansion coefficient between the glass (αg: 8.5☓10-6℃-1) and BTS crystal (αa: 5.7☓10-6℃-1, αc: 9.9☓10-6℃-1). Nanocrystallized Sm3+ doped BTS glass exhibited yellow-green (564 nm), orange (601 nm), red (647 nm, 709 nm) luminescences. Nanocrystallized BTS glass ceramic prepared by aerodynamic levitation is expected to utilize for optical devices, such as visible semiconductor laser, optical switch and amplifier. |
