Dual layered surface crystallization of 30BaO-15TiO2-55GeO 2 glass by stepwise heat treatment

Hirokazu Masai, Takumi Fujiwara, Hiroshi Mori, Yasuhiko Benino, Takayuki Komatsu

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11 Citations (Scopus)


In the crystallization process of 30BaO-15Ti O2 -55Ge O2 (BTG55), we demonstrated by an x-ray diffraction analysis that a stepwise heat treatment enables a selective crystallization of fresnoite and benitoite, two crystalline phases obtained from the BTG55 mother glass and that these two phases form a dual surface layer. The result indicates that the stepwise heat treatment generates a compositional heterogeneity inside the glass matrix, which facilitates the nucleation of the fresnoite phase. The mechanism for the generation of the dual surface layer is discussed. Due to a marked difference in optical nonlinearity of the two phases, the selective crystallization may open the possibility of an optimized heat-treatment condition to achieve a large optical nonlinearity in crystallized glass. Also, two types of fresnoite, tetragonal and orthorhombic, were observed in the crystallized phase after a stepwise heat treatment of 690720 °C.

Original languageEnglish
Article number123505
JournalJournal of Applied Physics
Issue number12
Publication statusPublished - 2007
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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