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Topological Phases, Boson mode, Immiscibility window and Structural Groupings in Ba-Borate and Ba-Borosilicate glasses

Holbrook, Chad M
http://orcid.org/0000-0002-9432-4043
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447070374

Abstract Details

2015, PhD, University of Cincinnati, Engineering and Applied Science: Electrical Engineering.
In a dry ambient,(BaO)x(B2O3)100-x (a pseudo-binary glass system) were synthesized over a wide composition range, 0 mol% < x < 40 mol% , by utilizing induction melting precursors. These high quality glasses were comprehensively examined in Modulated DSC, Raman Scattering, Infrared reflectance experiments. Raman Scattering experiments and the analysis of the symmetric stretch of intra-ring Boron-Oxygen (BO) bonds (A1’) of characteristic “mixed-rings”, permits the identification of Medium Range Structure (MRS) which form in the titled glasses. These modes consist of a triad of modes (705 cm-1, 740 cm-1 and 770 cm-1), and their scattering strengths display a positive correlation to the nucleation of characteristic structural groupings (SGs); analogous to structural groupings found in the corresponding crystalline phases of Barium-Tetraborate (x = 20 mol%), and Barium-Diborate (x = 33 mol%). Identification of the SG’s permit an understanding of the extended range structure apparent in these modified borate glasses. Furthermore, a microscopic understanding of the Immiscibility range in the titled glasses in the 0 mol% < x < 15 mol% range, can be traced to the deficiency of Barium that prohibits nucleation of the Barium-Tetraborate species. (BaO)x[32(B2O3)68(SiO2)]100-x (pseudo-ternary glasses) were synthesized and their Glass Transition Temperature (Tg(x)), molar volume (Vm(x)), and Raman Scattering were examined as a function of modifier (BaO) content in the 25 mol% < x < 48 mol% range. Three distinct regimes of behavior were observed: (1) At low x, 24 mol% < x < 29 mol% range, the modifier largely polymerizes the backbone, and Tg(x) increases. This is a feature that we identify with the stressed-rigid elastic phase. (2)At high x, 32 mol% < x < 48 mol% range, the modifier depolymerizes the network by creating non-bridging oxygen (NBO) atoms; in this regime, Tg(x) decreases and networks are viewed to be in the flexible elastic phase. (3) In the narrow intermediate x regime, 29 mol% < x < 32 mol% range, Tg(x) shows a broad global maximum (nearly x-independent), Vm(x) displays a global minimum, and Raman-modes (scattering-strengths and frequencies) become x-independent. These are features that we associate with the isostatically rigid elastic phase (also called the intermediate phase). In this phase, medium range structures adapt as revealed by the counting of Lagrangian bonding constraints and Raman Mode Scattering strengths.
Punit Boolchand, Ph.D. (Committee Chair)
Jonathan Goldstein, Ph.D. (Committee Member)
John S. Derov, Ph.D. (Committee Member)
Marc Cahay, Ph.D. (Committee Member)
Peter Kosel, Ph.D. (Committee Member)
131 p.
Electrical Engineering
Topological Phases; Boson mode; Immiscibility window; Structural Groupings; Barium Borate Glasses; Barium Borosilicate Glasses

Recommended Citations

Citations

  • Holbrook, C. M. (2015). Topological Phases, Boson mode, Immiscibility window and Structural Groupings in Ba-Borate and Ba-Borosilicate glasses [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447070374

    APA Style (7th edition)

  • Holbrook, Chad. Topological Phases, Boson mode, Immiscibility window and Structural Groupings in Ba-Borate and Ba-Borosilicate glasses. 2015. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447070374.

    MLA Style (8th edition)

  • Holbrook, Chad. "Topological Phases, Boson mode, Immiscibility window and Structural Groupings in Ba-Borate and Ba-Borosilicate glasses." Doctoral dissertation, University of Cincinnati, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447070374

    Chicago Manual of Style (17th edition)

ucin1447070374
522
© 2015, some rights reserved.Creative Commons License Topological Phases, Boson mode, Immiscibility window and Structural Groupings in Ba-Borate and Ba-Borosilicate glasses by Chad M Holbrook is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by University of Cincinnati and OhioLINK.