Katie Loughlin

Thesis Topic

X-ray diffraction for synthesis and crystallographic study of mayenite isostructures

Thesis

The mineral mayenite (Ca₁₂Al₁₄O₃₃), comprising a positively-charged network of cages which can be partially occupied by O^2- or a variety of other substituted anions or molecules, has a wide range of potential applications depending on the cage occupant.  The application that has garnered the most attention is substituting electrons in place of the O^2-anions resulting in an earth abundant, near transparent, conductive oxide.  In addition to the naturally occurring compound Ca₁₂Al₁₄O₃₃, the isostructural compounds Ca₁₂Ga₁₄O₃₃ and Sr₁₂Al₁₄O₃₃have been synthesized.  X-ray diffraction results suggest the cage size is increased from the naturally occurring compound suggesting that larger molecules can be occluded and/or the mobility of molecules through the cages can be altered.  My research combines using X-ray diffraction techniques to guide the synthesis of the Sr₁₂Al₁₄O₃₃ compound as well as to determine crystallographic details including the cage dimensions. The experimental studies are complemented by using MD and DFT modelling to understand occluded molecule mobility and how changing the framework cations will change the electronic properties.

Biography

I am currently an MSE PhD student in the research group of Dr. Claudia Rawn. I received my undergraduate degree from NC State University, where I majored in MSE and Spanish.  This year (2023-2024) is my third here in Knoxville. In addition to pursuing my PhD in Materials Science and Engineering, I am working towards the Interdisciplinary Graduate Minor in Computational Sciences (IGMCS).