La_(1.6)(MoO_4)_3∶Eu_(0.4)^(3+)纳米晶合成及发光特性

Synthesis and luminescence properties of La_(1.6)( MoO_4)_3:Eu_(0.4)^(3+) nanocrystal

采用燃烧法合成了La1.6(Mo O4)3∶Eu3+0.4纳米晶末,研究了其声子-掺杂-晶格相互作用和发光性质。X射线粉末衍射(XRD)分析表明,在500~900℃退火后,La1.6(Mo O4)3∶Eu3+0.4样品为单一晶相。对样品进行了光致发光(PL)测量,激发Mo6+-O2-电荷迁移带,观察到Eu3+的系列发光,表明Mo6+-O2-带和Eu3+间存在能量传递,中心波长分别在λ1=469 nm和λ2=426 nm处的两个one-phonon边带,相应的声子能量分别为767和1202 cm-1,分别对应于MoO和Mo—O—Mo伸缩振动。同时,计算了两个局域模电子-声子耦合强度的黄昆因子分别为S1=0.055和S2=0.037,为揭示其三价离子高传导特性及其负热膨胀物理特性提供了实验基础。

La1.6（MoO_4）_3：Eu0.4^3＋ nancrystal is synthesized by combustion method and the interaction between the phonon-dopant-lattice and luminescence properties of this nanocrystal are investigated. It is shown by X- ray diffraction that the powders are crystallized in a single phase annealed at 500 - 900℃. It is found that the excitation of the Mo^6 ＋ -O^2- charge transfer band （CTB） can result in the emissions of Eu^3 ＋ ion, which indi- cates that energy transfer takes place from CTB to Eu^3 ＋ ions. Two one-phonon sidebands locate at A1 = 469 nm and ,λ2 =426 nm in the excitation spectra which are due to Mo=O and Mo-O-Mo expand and contract vi- bration modes, respectively, with phonon energies of 1 202 cm-l and 767 cm-1. The Huang-Kun factors S1 = 0. 055 and S2 = 0. 037 describing the interaction intensity between phonon and lattice are determined. The op-tical properties of Lal.6 （MoO_4 ）_3：Eu_0.4^3＋ would be able to provide the experimental foundation to reveal the prop- erties of high conductivity and negative thermal expansion （NTE） with the trivalent ions.