Perfect surface crystallization and parasitic structures in nonstoichiometric glass-ceramics: Micro-anoscopic aspects

摘要

Uniform and highly oriented crystalline layers with submillimeter thickness have been demonstrated recently by crystallization in nonstoichiometric precursor glass, i.e., perfectly surface-crystallized glass-ceramics (PSC-GCs). Although the origin of PSC in the SrO-TiO_2-SiO_2 system was interpreted by the presence of SiO_2-rich amorphous nanoparasites on the crystalline domains [Takahashi et al., Sci. Rep. 3, 1147 (2013)], an essential question arose: Is the parasitic structure in PSC-GCs special or natural? To answer it, we prepared PSC samples from other ternary titanosilicate systems and conducted micro- and nanoscopic observations. We found the conditions necessary for PSC by combining our results with previous PSC studies.