The Experts below are selected from a list of 102 Experts worldwide ranked by ideXlab platform

Kazuhiko Kashima - One of the best experts on this subject based on the ideXlab platform.

  • in situ observation of bubble formation at silicon melt silica glass interface
    Journal of Crystal Growth, 2011
    Co-Authors: Toshiro Minami, Susumu Maeda, Mitsuo Higasa, Kazuhiko Kashima
    Abstract:

    Abstract The generation mechanism of pinhole defects in the Czochralski (CZ)-grown silicon (Si) single crystals was clarified by in-situ observations of bubble formation at the interface between Si melt and a silica glass crucible in a small experimental apparatus. The nucleation and growth of bubbles were facilitated by creating small cavities on the inner wall of the crucible. Si melting was conducted in an argon (Ar) atmosphere, and the pressure was maintained at either 100 Torr or close to a vacuum (no Ar-gas flow). It was found that in the presence of Ar, bubbles formed in the cavities immediately after the cavities came in contact with the melt. However, no bubbles formed in a vacuum in the experimental apparatus. These results indicate that the bubbles formed in the cavities are largely filled with Ar, and the initial bubble volumes are nearly comparable with those of the cavities. In an initial stage of expansion of a bubble, estimated volumes changed nearly in accordance with the Boyle–Charles Law. Further, participation of SiO gas in bubble growth may explain the deviation of the bubble volume from the theoretical value anticipated if only Ar gas was involved in the bubble growth.

  • In-situ observation of bubble formation at silicon melt–silica glass interface
    Journal of Crystal Growth, 2011
    Co-Authors: Toshiro Minami, Susumu Maeda, Mitsuo Higasa, Kazuhiko Kashima
    Abstract:

    Abstract The generation mechanism of pinhole defects in the Czochralski (CZ)-grown silicon (Si) single crystals was clarified by in-situ observations of bubble formation at the interface between Si melt and a silica glass crucible in a small experimental apparatus. The nucleation and growth of bubbles were facilitated by creating small cavities on the inner wall of the crucible. Si melting was conducted in an argon (Ar) atmosphere, and the pressure was maintained at either 100 Torr or close to a vacuum (no Ar-gas flow). It was found that in the presence of Ar, bubbles formed in the cavities immediately after the cavities came in contact with the melt. However, no bubbles formed in a vacuum in the experimental apparatus. These results indicate that the bubbles formed in the cavities are largely filled with Ar, and the initial bubble volumes are nearly comparable with those of the cavities. In an initial stage of expansion of a bubble, estimated volumes changed nearly in accordance with the Boyle–Charles Law. Further, participation of SiO gas in bubble growth may explain the deviation of the bubble volume from the theoretical value anticipated if only Ar gas was involved in the bubble growth.

Toshiro Minami - One of the best experts on this subject based on the ideXlab platform.

  • in situ observation of bubble formation at silicon melt silica glass interface
    Journal of Crystal Growth, 2011
    Co-Authors: Toshiro Minami, Susumu Maeda, Mitsuo Higasa, Kazuhiko Kashima
    Abstract:

    Abstract The generation mechanism of pinhole defects in the Czochralski (CZ)-grown silicon (Si) single crystals was clarified by in-situ observations of bubble formation at the interface between Si melt and a silica glass crucible in a small experimental apparatus. The nucleation and growth of bubbles were facilitated by creating small cavities on the inner wall of the crucible. Si melting was conducted in an argon (Ar) atmosphere, and the pressure was maintained at either 100 Torr or close to a vacuum (no Ar-gas flow). It was found that in the presence of Ar, bubbles formed in the cavities immediately after the cavities came in contact with the melt. However, no bubbles formed in a vacuum in the experimental apparatus. These results indicate that the bubbles formed in the cavities are largely filled with Ar, and the initial bubble volumes are nearly comparable with those of the cavities. In an initial stage of expansion of a bubble, estimated volumes changed nearly in accordance with the Boyle–Charles Law. Further, participation of SiO gas in bubble growth may explain the deviation of the bubble volume from the theoretical value anticipated if only Ar gas was involved in the bubble growth.

  • In-situ observation of bubble formation at silicon melt–silica glass interface
    Journal of Crystal Growth, 2011
    Co-Authors: Toshiro Minami, Susumu Maeda, Mitsuo Higasa, Kazuhiko Kashima
    Abstract:

    Abstract The generation mechanism of pinhole defects in the Czochralski (CZ)-grown silicon (Si) single crystals was clarified by in-situ observations of bubble formation at the interface between Si melt and a silica glass crucible in a small experimental apparatus. The nucleation and growth of bubbles were facilitated by creating small cavities on the inner wall of the crucible. Si melting was conducted in an argon (Ar) atmosphere, and the pressure was maintained at either 100 Torr or close to a vacuum (no Ar-gas flow). It was found that in the presence of Ar, bubbles formed in the cavities immediately after the cavities came in contact with the melt. However, no bubbles formed in a vacuum in the experimental apparatus. These results indicate that the bubbles formed in the cavities are largely filled with Ar, and the initial bubble volumes are nearly comparable with those of the cavities. In an initial stage of expansion of a bubble, estimated volumes changed nearly in accordance with the Boyle–Charles Law. Further, participation of SiO gas in bubble growth may explain the deviation of the bubble volume from the theoretical value anticipated if only Ar gas was involved in the bubble growth.

Susumu Maeda - One of the best experts on this subject based on the ideXlab platform.

  • in situ observation of bubble formation at silicon melt silica glass interface
    Journal of Crystal Growth, 2011
    Co-Authors: Toshiro Minami, Susumu Maeda, Mitsuo Higasa, Kazuhiko Kashima
    Abstract:

    Abstract The generation mechanism of pinhole defects in the Czochralski (CZ)-grown silicon (Si) single crystals was clarified by in-situ observations of bubble formation at the interface between Si melt and a silica glass crucible in a small experimental apparatus. The nucleation and growth of bubbles were facilitated by creating small cavities on the inner wall of the crucible. Si melting was conducted in an argon (Ar) atmosphere, and the pressure was maintained at either 100 Torr or close to a vacuum (no Ar-gas flow). It was found that in the presence of Ar, bubbles formed in the cavities immediately after the cavities came in contact with the melt. However, no bubbles formed in a vacuum in the experimental apparatus. These results indicate that the bubbles formed in the cavities are largely filled with Ar, and the initial bubble volumes are nearly comparable with those of the cavities. In an initial stage of expansion of a bubble, estimated volumes changed nearly in accordance with the Boyle–Charles Law. Further, participation of SiO gas in bubble growth may explain the deviation of the bubble volume from the theoretical value anticipated if only Ar gas was involved in the bubble growth.

  • In-situ observation of bubble formation at silicon melt–silica glass interface
    Journal of Crystal Growth, 2011
    Co-Authors: Toshiro Minami, Susumu Maeda, Mitsuo Higasa, Kazuhiko Kashima
    Abstract:

    Abstract The generation mechanism of pinhole defects in the Czochralski (CZ)-grown silicon (Si) single crystals was clarified by in-situ observations of bubble formation at the interface between Si melt and a silica glass crucible in a small experimental apparatus. The nucleation and growth of bubbles were facilitated by creating small cavities on the inner wall of the crucible. Si melting was conducted in an argon (Ar) atmosphere, and the pressure was maintained at either 100 Torr or close to a vacuum (no Ar-gas flow). It was found that in the presence of Ar, bubbles formed in the cavities immediately after the cavities came in contact with the melt. However, no bubbles formed in a vacuum in the experimental apparatus. These results indicate that the bubbles formed in the cavities are largely filled with Ar, and the initial bubble volumes are nearly comparable with those of the cavities. In an initial stage of expansion of a bubble, estimated volumes changed nearly in accordance with the Boyle–Charles Law. Further, participation of SiO gas in bubble growth may explain the deviation of the bubble volume from the theoretical value anticipated if only Ar gas was involved in the bubble growth.

Mitsuo Higasa - One of the best experts on this subject based on the ideXlab platform.

  • in situ observation of bubble formation at silicon melt silica glass interface
    Journal of Crystal Growth, 2011
    Co-Authors: Toshiro Minami, Susumu Maeda, Mitsuo Higasa, Kazuhiko Kashima
    Abstract:

    Abstract The generation mechanism of pinhole defects in the Czochralski (CZ)-grown silicon (Si) single crystals was clarified by in-situ observations of bubble formation at the interface between Si melt and a silica glass crucible in a small experimental apparatus. The nucleation and growth of bubbles were facilitated by creating small cavities on the inner wall of the crucible. Si melting was conducted in an argon (Ar) atmosphere, and the pressure was maintained at either 100 Torr or close to a vacuum (no Ar-gas flow). It was found that in the presence of Ar, bubbles formed in the cavities immediately after the cavities came in contact with the melt. However, no bubbles formed in a vacuum in the experimental apparatus. These results indicate that the bubbles formed in the cavities are largely filled with Ar, and the initial bubble volumes are nearly comparable with those of the cavities. In an initial stage of expansion of a bubble, estimated volumes changed nearly in accordance with the Boyle–Charles Law. Further, participation of SiO gas in bubble growth may explain the deviation of the bubble volume from the theoretical value anticipated if only Ar gas was involved in the bubble growth.

  • In-situ observation of bubble formation at silicon melt–silica glass interface
    Journal of Crystal Growth, 2011
    Co-Authors: Toshiro Minami, Susumu Maeda, Mitsuo Higasa, Kazuhiko Kashima
    Abstract:

    Abstract The generation mechanism of pinhole defects in the Czochralski (CZ)-grown silicon (Si) single crystals was clarified by in-situ observations of bubble formation at the interface between Si melt and a silica glass crucible in a small experimental apparatus. The nucleation and growth of bubbles were facilitated by creating small cavities on the inner wall of the crucible. Si melting was conducted in an argon (Ar) atmosphere, and the pressure was maintained at either 100 Torr or close to a vacuum (no Ar-gas flow). It was found that in the presence of Ar, bubbles formed in the cavities immediately after the cavities came in contact with the melt. However, no bubbles formed in a vacuum in the experimental apparatus. These results indicate that the bubbles formed in the cavities are largely filled with Ar, and the initial bubble volumes are nearly comparable with those of the cavities. In an initial stage of expansion of a bubble, estimated volumes changed nearly in accordance with the Boyle–Charles Law. Further, participation of SiO gas in bubble growth may explain the deviation of the bubble volume from the theoretical value anticipated if only Ar gas was involved in the bubble growth.

Zhushan Shao - One of the best experts on this subject based on the ideXlab platform.

  • Investigation of Macroscopic Brittle Creep Failure Caused by Microcrack Growth Under Step Loading and Unloading in Rocks
    Rock Mechanics and Rock Engineering, 2016
    Co-Authors: Zhushan Shao
    Abstract:

    The growth of subcritical cracks plays an important role in the creep of brittle rock. The stress path has a great influence on creep properties. A micromechanics-based model is presented to study the effect of the stress path on creep properties. The microcrack model of Ashby and Sammis, Charles’ Law, and a new micro–macro relation are employed in our model. This new micro–macro relation is proposed by using the correlation between the micromechanical and macroscopic definition of damage. A stress path function is also introduced by the relationship between stress and time. Theoretical expressions of the stress–strain relationship and creep behavior are derived. The effects of confining pressure on the stress–strain relationship are studied. Crack initiation stress and peak stress are achieved under different confining pressures. The applied constant stress that could cause creep behavior is predicted. Creep properties are studied under the step loading of axial stress or the unloading of confining pressure. Rationality of the micromechanics-based model is verified by the experimental results of Jinping marble. Furthermore, the effects of model parameters and the unloading rate of confining pressure on creep behavior are analyzed. The coupling effect of step axial stress and confining pressure on creep failure is also discussed. The results provide implications on the deformation behavior and time-delayed rockburst mechanism caused by microcrack growth on surrounding rocks during deep underground excavations.