Coe College
2019
SPS Award for Outstanding Undergraduate Research
Thermal and Structural Properties of Alkali Oxide Modified Tellurite Glasses
My name is Martha Jesuit. I’m from Clarence, Iowa and I’m currently a rising junior at Coe College studying physics and math. On campus, I’m involved in physics and math club, band, choir, track and field, Tridelta sorority, and WinSTEM club.
The structural and thermal properties of lithium, sodium, and potassium tellurite glasses, written as JM2O-TeO2 where M is an alkali metal, were studied. Raman spectra were measured on all glasses along with the glass transition onset (Tg), crystallization (Tx), and melting (Tm) temperatures. All thermal measurements were measured on a Perkin-Elmer DSC-7. The thermal measurements were compared to the coordination of the tellurium. Coordination data was found by deconvoluting Raman spectra using Igor Pro to find the percent of Q4 and Q3 units in the glass. Pure amorphous TeO2 was made using the water-quenching method then thermally tested against time to observe how the glass transition onset and crystallization changed. We measured Tx and Tg every 30 minutes on glassy TeO2. Since TeO2 has a strong crystallization tendency, the samples were prepared in a nitrogen glovebox to minimize the effect of water on the recrystallization. Future work includes x-ray and neutron diffraction to learn more about the structure of this these hard to make glasses.