Multi-elemental segregation analysis of thallium bromide impurities purified by the repeated Bridgman technique

TlBr crystals were purified and grown by the repeated Bridgman method from commercial TlBr salt and characterized to be used as radiation detectors. To evaluate the purification efficiency, measurements of the impurity concentration were made after each growth, analyzing the trace impurities by inductively coupled plasma mass spectroscopy (ICP-MS). A significant decrease of the impurity concentration resulting from the purification number was observed. To evaluate the crystal as a radiation semiconductor detector, measurements of its resistivity and gamma-ray spectroscopy were carried out. The radiation response depended on the crystal purity. The repeated Bridgman technique improved the TIBr crystal quality used as a radiation detector. An exponential model was used to fit the impurity concentration as a function of the repetition number of the Bridgman growth.