Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Dalton Trans. 2012 Oct 21;41(39):12023-30. doi: 10.1039/c2dt30691c.
The present study describes the structural and luminescent properties of SrSnO(3) nanorods containing Eu(3+) ions. Based on Rietveld refinement of XRD patterns corresponding to both undoped and europium doped SrSnO(3) nanorods, it is inferred that the average bond lengths of Sr-O1 linkages, which have a square planar geometry around Sr(2+) in the SrO(12) polyhedra present in SrSnO(3), remained unaffected with Eu(3+) incorporation into the lattice. However, the average bond lengths of shorter Sr-O2 linkages increase and longer Sr-O2 linkages decrease with Eu(3+) doping into the SrSnO(3) lattice. A lack of variation in the lattice parameters of SrSnO(3) with doped Eu(3+) ions is explained based on mutually compensating changes in the average bond lengths of the Sr-O2 linkages in the unit cell. Luminescence studies have confirmed that Eu(3+) ions occupy the centrosymmetric Sr(2+) site only up to 2 at%, beyond which Eu(3+) ions exist in a significantly distorted environment (grain boundaries). Beyond 3%, incorporation of Eu(3+) ions into the SrSnO(3) lattice leads to the formation of a Eu(2)Sn(2)O(7) phase. From the EPR studies it is confirmed that around 5% of the incorporated Eu(3+) ions get converted to Eu(2+) ions and they occupy Sr(2+) sites in the lattice.
本研究描述了含有 Eu(3+)离子的 SrSnO(3)纳米棒的结构和发光性能。基于对未掺杂和铕掺杂 SrSnO(3)纳米棒的 XRD 图谱的 Rietveld 精修，推断出 Sr-O1 键的平均键长在 SrSnO(3)晶格中掺入 Eu(3+)后保持不变，因为 Sr(2+)周围的 SrO(12)多面体具有正方形平面几何形状。然而，较短的 Sr-O2 键的平均键长增加，较长的 Sr-O2 键的平均键长减少。Eu(3+)掺杂到 SrSnO(3)晶格中时，SrSnO(3)的晶格参数没有变化，这可以根据晶胞中 Sr-O2 键的平均键长的相互补偿变化来解释。发光研究证实，Eu(3+)离子仅占据中心对称的 Sr(2+)位，直到 2%，超过该浓度，Eu(3+)离子存在于明显扭曲的环境（晶界）中。Eu(3+)离子掺入 SrSnO(3)晶格超过 3%会导致形成 Eu(2)Sn(2)O(7)相。从 EPR 研究中证实，大约 5%的掺入的 Eu(3+)离子转化为 Eu(2+)离子，它们占据晶格中的 Sr(2+)位。
