Masters Theses

Date of Award

12-2013

Degree Type

Thesis

Degree Name

Master of Science

Major

Materials Science and Engineering

Major Professor

Mariya Zhuravleva

Committee Members

Charles L. Melcher, Claudia J. Rawn

Abstract

Scintillators are widely used in homeland security applications that utilize gamma-ray spectroscopy. An ideal scintillator for this purpose should possess a high effective atomic number, high light yield, and good energy resolution. The scintillator CsSrI3: Eu [cesium strontium iodide: europium], recently developed at the Scintillation Materials Research Center, has excellent properties. Recent efforts have been made to evaluate the basic thermal properties and IR spectra of the compound’s raw materials as part of a project to improve the quality of grown crystals. Fourier transform infrared spectroscopy of high purity anhydrous CsI [cesium iodide], SrI2 [strontium iodide], and EuI2 [europium iodide] raw materials revealed the presence of oxygen and moisture impurities. The presence of the hydroxyl impurity is particularly detrimental to CsSrI3: Eu [cesium strontium iodide: europium] because it is hygroscopic, and can have a deleterious effect on the overall crystal quality. Even though the as-received raw materials are anhydrous, they contain some residual hydroxyl impurities, and benefit from a drying procedure. It is important to know how the raw materials used for this compound behave as a function of temperature so that the best possible drying conditions can be discovered. Differential scanning calorimetry and thermogravimetric analysis were used in conjunction to determine optimal drying conditions. The hygroscopicity of the raw materials was also determined. Multiple samples were synthesized to study the effects of drying on this scintillator. This study allows a broader understanding of the challenges to overcome in order to improve this promising scintillation material.

Comments

Something that I am still not clear on, and hope you can help me understand. I saw in the revisions that you asked me to do that any of the figures or tables should be at least a half-inch from any other text. Does that include page numbers?

Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS