Thermoluminescence characterization of Ag-doped Li2B4O7 single crystal materials

Abstract

In this study the thermoluminescence (TL) characteristics of Ag-doped and undoped lithium tetraborate (Li2B4O7 LTB) materials grown using the Czochralski method were reported. The TL properties of LTB:Ag such as glow curve structure dose response fading and reproducibility were investigated. The glow curve of the Li2B4O7:Ag single crystal consists of four peaks located at approximately 75 130 190 and 275 degrees C, in undoped LTB the single crystal shows a broad glow curve with peaks at 65 90 125 160 and 190 degrees C using a heating rate of 5 degrees C/s in the 50-350 degrees C temperature region. The high temperature peak of Ag-doped sample at 275 degrees C has a nonlinear dose response within the range from 33mGy to 9Gy. There is a linear response in the range of 33-800mGy, after which a sublinear region appears up to 9Gy for Ag-doped LTB single crystal. For undoped single crystal the dose response is supralinear for low doses and linear for the region between 1 and 9Gy. The thermal fading ratio of the undoped material is almost 60% for the high temperature peak after 7days. Ag-doped LTB single crystal exhibits different behaviour over a period of 7days.