Abstract
Thermoluminescence (TL) emission from undoped and sodium doped α- and β-BaB 2O 4 (BBO) crystals has been investigated. A single TL glow peak is observed for the undoped crystals of both phases. The glow peak temperatures found for α- and β-BBO crystals over the temperature range 35–300°C are 104 and 80°C, respectively. The presence of minute amount of sodium ions in the lattice gives rise to a glow peak around 200°C. For impurity concentrations higher than 0.02% (by wt), additional glow peaks around 123 and 240°C are also observed. The ratio of the TL intensities corresponding to the first and 200°C peaks is observed to increase with impurity concentration. This fact provides an easy and sensitive method of detecting the presence of sodium ions in BBO lattice. The results also show that sodium ions go substitutionally into the lattice and act as charge traps. The optical absorption in the ultra violet region and the crystal hardness towards ionizing radiations are found to be adversely affected by the presence of this impurity.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have