Ab initio lattice relaxation and compensation mechanism for the lightly fluorine doped PbWO4

Abstract

AbstractThe lattice structure of lightly F–‐doped PbWO4 (F–:PWO) crystal is optimized within the framework of density functional theory. The lattice relaxation results demonstrate that the F– ion and two longer‐bond O2– ions shift towards VPb2–, while other O2– ions and cations Pb2+ and W6+ shift outwards. By analyzing the electronic structure of lightly F–:PWO crystals, the role of the F– in F–:PWO is revealed and it can also be concluded that the two longer‐bond O2– could share a hole forming a diatomic molecular ion O23–. Thus the VPb2– is completely compensated by a F– ion and a diatomic molecular ion O23–. Thus the doping of the F– ion could effectively restrict the formation of [O23––VPb–O23–] and weaken the 420 nm absorption band and improve the scintillation property of the PWO. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)