Phase transition process and luminescent properties of undoped and Dy3+ ion doped orthorhombic PbF2 prepared by a hydrothermal method

Abstract

Orthorhombic (α) SSPbF2 microcrystal was synthesized by a normal hydrothermal method. The influence of F/Pb ratio and hydrothermal reaction time on the crystal phase of the acquired PbF2 samples were discussed, and a β to α phase transition was found according to the XRD results. The undoped α-PbF2 powder showed a broad but weak emission band around 450–570nm, which was due to (Pb2)3+ nearest neighbor pair centers. Dy3+ ion doped α-PbF2 samples showed main emission bands at 480nm and 574nm, which were assigned to the transitions from 4F9/2 to 6H15/2 and 6H13/2 of Dy3+, respectively. Furthermore, the morphology and crystalline properties of the undoped and Dy3+ doped α-PbF2 microcrystal powder were also discussed carefully. The decay time results combined with the X-ray excitation results suggested that Dy3+ ion doped α-PbF2 is a useful scintillating material for high energy physics applications, such as X-ray scintillating panel, etc.