### 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 SrOGeO_{2}, CaOGeO_{2} and PbOGeO_{2} 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 language | English |
---|---|

Pages (from-to) | 108-116 |

Number of pages | 9 |

Journal | Journal of Non-Crystalline Solids |

Volume | 103 |

Issue number | 1 |

DOIs | |

Publication status | Published - Jun 2 1988 |

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### All Science Journal Classification (ASJC) codes

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

### Cite this

*Journal of Non-Crystalline Solids*,

*103*(1), 108-116. https://doi.org/10.1016/0022-3093(88)90422-X

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

Research output: Contribution to journal › Article

*Journal of Non-Crystalline Solids*, vol. 103, no. 1, pp. 108-116. https://doi.org/10.1016/0022-3093(88)90422-X

}

TY - JOUR

T1 - Phase separation in germanate glasses

AU - Morinaga, Kenji

AU - Nakashima, Kunihiko

PY - 1988/6/2

Y1 - 1988/6/2

N2 - 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.

AB - 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.

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U2 - 10.1016/0022-3093(88)90422-X

DO - 10.1016/0022-3093(88)90422-X

M3 - Article

AN - SCOPUS:30244512778

VL - 103

SP - 108

EP - 116

JO - Journal of Non-Crystalline Solids

JF - Journal of Non-Crystalline Solids

SN - 0022-3093

IS - 1

ER -