摘要
钨酸铅晶体是一种非化学计量化合物,缺陷丰富,蕴含着利用掺杂产生新效应和开发新功能的广泛可能性。探讨了不同浓度La3+掺杂对于钨酸铅晶体发光性能的影响,如热释光、X射线激发发光、光致发光等。La3+掺杂有效地抑制了陷阱中心,使发光受到强烈的抑制,在高浓度掺杂的钨酸铅中,激发机制有所改变,通过XPS测试的结果分析了不同浓度La3+掺杂机制。低浓度掺杂中,La3+取代Pb2+,形成缺陷复合体[2(La3Pb+).-(VPb)″];高浓度掺杂晶体中,La3+离子不但占据Pb2+位置,而且也会占据W6+位置(La3W+),产生La3+的自补偿机制,形成La3+的自补偿对[(La3W+)-(La3Pb+).]-(VO)..或缺陷聚集体[3(LaP3b+).-(La3W+)]。
Lead tungstate, PbWO4, is a nonstoichiometric single crystal with many defects. Doping is the most important method to improve the scintillating properties. In this paper, X-ray excited luminescence, thermoluminescence and photohiminescence have been investigated for La^3＋ -doped PbWO4. La^3＋ doping significantly depressed luminescence of PWO. Doping in low concentrations, La^3＋ substitutes Pb^2＋ sites with excess charge compensated by intrinsic Vpb for the formation of defect complexes [2（Lapb^3＋）-V＂pb]. Upon higher La^3＋ doping, La^3＋ would occupy W-sites with＇the exception of Pb-sites and cause charge compensation not only by [2（Lapb^3＋）-V＂pb], but also by La^3＋ self-compensation pairs [（Law）＇＇＇-（Lapb）＇ ]-（Vo）＂ or cluster [3 （Lapb）＇-（Law）＇＇＇], where new nonradiative recombination occurs and the luminescence of PWO is intensively suppressed. This doping mechanism is discussed in terms of X-ray photoelectron spectroscopical experiments.
出处
《矿物学报》
CAS
CSCD
北大核心
2006年第1期84-88,共5页
Acta Mineralogica Sinica
