Site Dependence of Tb3+ Luminescence in Double Perovskite-Type Alkaline Earth Lanthanum Tantalates
Site Dependence of Tb3+ Luminescence in Double Perovskite-Type Alkaline Earth Lanthanum Tantalates
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双钙钛矿型碱土钽酸镧中 Tb3 发光的位点依赖性
DOI：
10.1021/acs.jpcc.9b09260
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Jobic Stephane
中科院分区：
文献类型：
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作者：
Ueda Kazushige;Tanaka Syuto;Yamamoto Ryo;Shimizu Yuhei;Honma Tetsuo;Massuyeau Florian;Jobic Stephane
制备了具有B位有序双钙钛矿型结构(AA′)[BB′]O6的Tb3+掺杂碱土钽酸盐(即(CaLa1–xTbx)[CaTa]O6(CLTO:Tb3+)和Ba2[La1–xTbxTa]O6(BLTO:Tb3+)，其中x= 0.01、0.10)，并对其进行了研究。根据占据的晶体位点（A 或 B 位点）检查并解释了 Tb3+ 光致发光 (PL) 特性。通过分析粉末 X 射线衍射图和 Tb LIIIedge 边缘结构附近的 X 射线吸收，阐明了 Tb3+ 激活剂的位置。 Tb3+ 离子位于 CLTO:Tb3+ 中的 A 位点和 BLTO:Tb3+ 中的 B 位点，如标称组成所示。由于 Tb3+ 的 4f-5d 激发，CLTO:Tb3+ 和 BLTO:Tb3+ 在 UV 区域均表现出强烈的 PL 激发 (PLE) 峰。与 CLTO:Tb3+ 中的相比，BLTO:Tb3+ 中 Tb3+ 的 PLE 峰显示出明显的红移，这主要是因为 B 位点的晶场比 A 位点更大。与从 5D4 到 7F5 态的 4f-4f 转变相关的主要 PL 峰也受到晶体场的影响，并且 BLTO:Tb3+ 中 B 位点处 Tb3+ PL 峰的分裂比 CLTO:Tb3+ 中 A 位点处的 PL 峰分裂更明显。此外，由于 Tb 5d 轨道的下移，源自 5D3-7FJ 跃迁的蓝色区域中的 PL 在 BLTO:Tb3+ 中被 Tb3+ 淬灭。
Tb3+doped alkaline earth lanthanum tantalates with the B-site-ordered double perovskite-type structure (AA′)[BB′]O6(namely, (CaLa1–xTbx)[CaTa]O6(CLTO:Tb3+) and Ba2[La1–xTbxTa]O6(BLTO:Tb3+) withx= 0.01, 0.10) were prepared, and their Tb3+photoluminescence (PL) properties were examined and explained based on the occupied crystal sites (A or B sites). The locations of the Tb3+activators were elucidated by analyzing powder X-ray diffraction patterns and X-ray absorption near edge structure at the Tb LIIIedge. Tb3+ions are located at A sites in CLTO:Tb3+and at B sites in BLTO:Tb3+as indicated in the nominal compositions. Both CLTO:Tb3+and BLTO:Tb3+exhibited intense PL excitation (PLE) peaks in the UV region due to the 4f–5d excitation for Tb3+. The PLE peak of Tb3+in BLTO:Tb3+showed a marked red-shift compared to that in CLTO:Tb3+primarily because of the larger crystal fields at the B sites than at the A sites. The main PL peaks associated with the 4f–4f transitions from5D4to7F5states are also influenced by the crystal field, and the splitting of the PL peaks for Tb3+at the B sites in BLTO:Tb3+is more pronounced than that at the A sites in CLTO:Tb3+. In addition, owing to a downshift of the Tb 5d orbitals, the PL in the blue region derived from5D3–7FJtransitions is quenched for Tb3+in BLTO:Tb3+.