Open AccessThe colour centre model related to lead vacancy in PbWO4 crystal
Author(s) -
Tingyu Liu,
Qiren Zhang,
Zhuang Song-Lin
Publication year - 2005
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.54.863
Subject(s) - crystal (programming language) , physics , vacancy defect , lattice (music) , density functional theory , condensed matter physics , materials science , molecular physics , atomic physics , quantum mechanics , computer science , acoustics , programming language
The local structure geometry around a lead vacancy V2-Pb in PbWO 4 is optimized using a planewave pseudopotential formulation within the fr amework of local density approximation (LDA), with generalized gradient correcti on in the form of Perdew_Wang_91 The results of the lattice relaxation decreas e the electrical negativity on V2-Pb site and increase the elect rical positivity on O2- site near by the V2-Pb. All of the electronic structures around V2-Pb in PWO crystal are studied i n the molecular_cluster model with the framework of the fully relativistic self_ consistent Direc_Slater theory by using a numerically discrete variational (DV_X α) method. By analyzing the electronic structures, we can reasonably believe th at once V2-Pb is formed in PWO crystal, O2- turns to be pr ior to trap holes to compensate the electrical negativity of V2-Pb . Pb2+ may never be the holetrapper compensating V2-Pb , and Pb3+ and Pb4+ in PWO crystal may not actually exist. The possi ble defect micromodel caused by V2-Pb in the asgrown PWO cry stal is that each V2-Pb creates a VKV-F aggr egate color center.