Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1481555 | Journal of Non-Crystalline Solids | 2012 | 7 Pages |
The morphology and dispersion state of Ba2TiSi2O8 (BTS) nanocrystals in transparent glass-ceramics (composition: 40BaO–20TiO2–40SiO2) were examined from high resolution transmission electron microscope observations, and their nano-scale deformation behavior was examined using Berkovich nanoindentation technique (standard-type and continuous stiffness measurement (CSM)-type). In the early stage of crystallization, BTS crystalline layers with a thickness of ~ 120 nm were formed at the surface and ellipsoid-shaped crystallites with a diameter of 100–200 nm were dispersed in the glass matrix. In the late stage, BTS crystals with a diameter of 200–400 nm were formed densely, but a glassy phase was present between BTS crystals. The Young's modulus evaluated from CSM-type nanoindentation measurements for a deformation scale of about 100 nm shows the values of 98 GPa for the glass and 110 GPa for the glass-ceramics with nanocrystals. It was suggested that CSM-type measurements are very sensitive in the nano-scaled homogeneity in the heat-treated samples.
► Morphology and dispersion state of Ba2TiSi2O8 nanocrystals in glass-ceramics were clarified. ► Nano-scale deformation behavior was examined using Berkovich nanoindentation technique. ► In the early stage of crystallization, ellipsoid-shaped nanocrystallites were dispersed. ► CSM-type measurements are sensitive in the nano-scaled homogeneity in the samples.