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Evidence for the Intermediate Phase in Bulk (K2O)x(GeO2)1-x glasses and its consequences on Electrical and Thermal Properties

Wang, Ninghua

Abstract Details

2007, MS, University of Cincinnati, Engineering : Electrical Engineering.

Knowledge on elastic phase transitions is the key to understanding the basic structure and properties of network glass systems. Generally, one can classify the inorganic glasses into three distinct phases, flexible-intermediate-stressed rigid, based on coordinates of the Lagrangian bonding constrains per atom, nc. Optimally constrained networks are characterized as nc =3, and labeled as Intermediate Phase. Those having nc < 3 are structurally flexible and those with nc > 3 are stressed-rigid in nature.

In Potassium Germante glasses, an Intermediate Phase is observed in these glasses in the composition range 4% < x < 9%, where glasses transitions become thermally reversing. Trends of glass transition temperature (Tg), specific heat jump (ΔCp) and non-reversing enthalpy at Tg, ΔHnr , are recorded.

Raman and IR spectroscopies are applied on present glasses and an optical elasticity power-law is deduced in the intermediate phase. From electrical conductivity measurement two conclusions are derived: first, conductivity jumps concur near x = 4% and x = 9% at the elastic phase boundaries; second, conductivity increase as a power-law in flexible glasses(x > 9%). Molar volume show a minimum when glasses enter the flexible phase.

Present thermal, optical, electrical and mechanical experiments suggest that the Germanate Anomaly a result of the Intermediate Phase. However, connections to theory and fine structure in local and medium ranges are open to discussion.

Dr. Punit Boolchand (Advisor)
84 p.

Recommended Citations

Citations

  • Wang, N. (2007). Evidence for the Intermediate Phase in Bulk (K2O)x(GeO2)1-x glasses and its consequences on Electrical and Thermal Properties [Master's thesis, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1187020710

    APA Style (7th edition)

  • Wang, Ninghua. Evidence for the Intermediate Phase in Bulk (K2O)x(GeO2)1-x glasses and its consequences on Electrical and Thermal Properties. 2007. University of Cincinnati, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1187020710.

    MLA Style (8th edition)

  • Wang, Ninghua. "Evidence for the Intermediate Phase in Bulk (K2O)x(GeO2)1-x glasses and its consequences on Electrical and Thermal Properties." Master's thesis, University of Cincinnati, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1187020710

    Chicago Manual of Style (17th edition)