Phase separation in germanate glasses

Kenji Morinaga, Kunihiko Nakashima

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Applying the hot-thermocouple method, the TTT diagrams were determined by observing the time change of the phase separation and the crystallization in the supercooled liquids of SrOGeO2, CaOGeO2 and PbOGeO2 systems as examples. The nucleation-growth type phase-separation with a binodal curve between the liquidus and crystallization temperature is observed. Moreover, the growth mechanism of the nucleation-growth type phase separation was discussed in terms of the occupied volume fraction of particles. The results obtained are summarized as follows below. Therefore, in the initial stage of growth, an average radius r of particles changes with the square root of time (r ∝ t 1 2) in every composition. But in the later stage of growth, an average radius r of particles growth with the cubic root of time (r ∝ t 1 3) corresponding to Ostwald ripening in the range of the small volume fraction within about 20%. On the other hand, in the range of the high volume fraction above about 20%, an average radius r of particles grows faster in proportion to their volume fraction by the process of connect and coalescence. The results of our experiment in the range of the high volume fraction can be represented by Furukawa's theory for a binary fluid mixture. One may presume that the growth mechanism of particles is divided in the range of small volume fraction and in the range of high volume fraction.

Original languageEnglish
Pages (from-to)108-116
Number of pages9
JournalJournal of Non-Crystalline Solids
Volume103
Issue number1
DOIs
Publication statusPublished - Jun 2 1988

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Phase separation
Volume fraction
Glass
glass
Crystallization
radii
Nucleation
nucleation
crystallization
Ostwald ripening
binary fluids
liquidus
thermocouples
Thermocouples
Coalescence
coalescing
proportion
diagrams
Fluids
Liquids

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Materials Chemistry

Cite this

Phase separation in germanate glasses. / Morinaga, Kenji; Nakashima, Kunihiko.

In: Journal of Non-Crystalline Solids, Vol. 103, No. 1, 02.06.1988, p. 108-116.

Research output: Contribution to journalArticle

Morinaga, Kenji ; Nakashima, Kunihiko. / Phase separation in germanate glasses. In: Journal of Non-Crystalline Solids. 1988 ; Vol. 103, No. 1. pp. 108-116.
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