Subcategory: Materials Science
Samuel Uba - Alabama A&M University
Co-Author(s): Stephen Babalola, Alabama A&M University
High-performance detectors used in the detection of ionizing radiation is critical to nuclear nonproliferation applications and other radiation detectors applications. In this research, we grew and tested Europium doped Lithium Strontium Iodide compound. A mixture of lithium iodide, strontium iodide, and europium iodide was used as the starting materials for this research. Congruent melting and freezing temperature of the synthesized compound was determined by differential scanning calorimetry (DSC) using a Setaram Labsys Evo DSC-DTA instrument. The melting temperatures were recorded at 390.35°C, 407.59°C and freezing temperature was recorded at 322.84°C from a graph of heat flow plotted against temperature. The synthesized material was used as the charge for the vertical Bridgeman growth, and a 6.5 cm and 7.7cm length boule were grown in a multi-zone transparent Mullen furnace. A scintillating detector of thickness 2.53mm was fabricated by mechanical lapping in mineral oil, and scintillating response and timing were obtained to a cesium source using CS-137 isotope. An energy resolution (FWHM over peak position) of 12.1% was observed for the 662keV full absorption peak. Optical absorption in the UV-Vis wavelength range was recorded for the grown crystal using a U-2900 UV/VIS Spectrophotometer. Absorption peaks were recorded at 194nm, 273nm, and 344nm from the absorbance spectrum, various optical parameters such as absorption coefficient, extinction coefficient, refractive index, and optical loss were derived. The optical band gap energy was calculated using Tauc relation expression at 1.79eV.
Funder Acknowledgement(s): DOE (Department of Energy) AL-RISE Foundation
Faculty Advisor: Stephen Babalola, email@example.com
Role: Crystal Growth, Optical, and Structural Characterization.