University of Rochester
Inman, Jill Marie (1967 - ).
Ion exchange and chemical structure in glass.
Degree: PhD, 2017, University of Rochester
Ion exchange techniques are often used in the
fabrication of devices for photonic applications, such as
micro-optics and waveguides. However, device performance depends on
the ability to predict and control the exchange to achieve the
desired concentration profile. In many glass systems, the diffusion
coefficient is strongly dependent on the dopant concentration. This
is a manifestation of the Mixed Mobile Ion Effect (MMIE). Although
the MMTE may be viewed mostly as an unwanted complication for
waveguide fabrication, its presence is required for fabrication of
microoptics, where a concentration dependence is needed to achieve
the necessary profiles. However, to date it has most often been
characterized only empirically - improved methods of describing,
predicting and controlling ion exchanges for micro-optics are
needed. In this work, the relationship between this concentration
dependence and the chemical structure of the glass is examined in
the commercially-important silver-for-sodium ion exchange pair. The
research utilized three approaches to investigate diffusion
structure/properties relationships: structural investigations,
modeling of the concentration dependence and studies measuring the
diffusion coefficient. X-ray Absorption Fine Structure (XAFS)
studies were performed on the environments of the mobile cations in
silicate glasses. These studies are used to help formulate a
structural picture of ion exchange in which the interactions
between the mobile cations affect ion transport rates. This
structural picture is related to the diffusion rate through the use
of the Modified Quasi-Chemical (MQC) Diffusion Coefficient, a new
formulation that models the diffusion coefficient based on cation
mobilities, the number of nearest cation neighbors and
cation-cation interaction energies. The MQC expression successfully
models the strong concentration dependence observed in real glass
systems. This model is applied to ion exchanges performed into
endpoint glasses of a sodium aluminosilicate series. It is found
that the non-bridging oxygen (NBO) content of the glass has a major
impact on both the chemical structure of the glass and the
concentration dependence of the diffusion coefficient.
Specifically, the NBO-rich glass has the highest excess interaction
energy and exhibits the greatest MMIE, consistent with the
to Zotero / EndNote / Reference
APA (6th Edition):
Inman, J. M. (. -. ). (2017). Ion exchange and chemical structure in glass. (Doctoral Dissertation). University of Rochester. Retrieved from http://hdl.handle.net/1802/32180
Chicago Manual of Style (16th Edition):
Inman, Jill Marie (1967 - ). “Ion exchange and chemical structure in glass.” 2017. Doctoral Dissertation, University of Rochester. Accessed March 30, 2017.
MLA Handbook (7th Edition):
Inman, Jill Marie (1967 - ). “Ion exchange and chemical structure in glass.” 2017. Web. 30 Mar 2017.
Inman JM(-). Ion exchange and chemical structure in glass. [Internet] [Doctoral dissertation]. University of Rochester; 2017. [cited 2017 Mar 30].
Available from: http://hdl.handle.net/1802/32180.
Council of Science Editors:
Inman JM(-). Ion exchange and chemical structure in glass. [Doctoral Dissertation]. University of Rochester; 2017. Available from: http://hdl.handle.net/1802/32180