Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education , Northeastern University , Shenyang , Liaoning 110819 , China.
Institute for Ceramics and Powder Metallurgy, School of Materials Science and Engineering , Northeastern University , Shenyang , Liaoning 110819 , China.
Inorg Chem. 2018 Sep 4;57(17):10791-10801. doi: 10.1021/acs.inorgchem.8b01427. Epub 2018 Aug 15.
Hydrothermally reacting Lu(NO) and NaWO·2HO at 200 °C and pH = 8 produced the new compound NaLuWO·2HO, which was analyzed via the Rietveld technique to crystallize in the orthorhombic system (space group: Cmmm) with cell parameters a = 21.655(1), b = 5.1352(3), and c = 3.6320(2) Å and cell volume V = 403.87(4) Å. The crystal structure presents -(NaO)-(NaO)- and -(LuO(HO)WO)-(LuO(HO)WO)- alternating layers linked together by the O ion common to NaO octahedron and WO triangle bipyramid. Tetragonal structured and phase-pure Na(LuLnYb)(WO) phosphors (Ln = Ho, Er, and Tm) were directly produced by calcining their NaLuWO·2HO analogous precursors at 600 °C for 2 h, followed by a detailed study of their downconversion/upconversion (DC/UC) photoluminescence. It was shown that the UC luminescence is dominated by a red band at ∼650 nm for Ho (F → I transition), green bands at ∼500-575 nm for Er (H/S → I transitions) and a blue band at ∼476 nm for Tm (G → H transition), all via a three-photon process. DC luminescence of the phosphors is characterized by a ∼545 nm green emission for Ho (F/S → I transition, λ = 453 nm), ∼500-575 nm green emissions for Er (H/S → I transitions, λ = 380 nm), and a ∼455 nm blue emission for Tm (D → F transition, λ = 360 nm), with CIE chromaticity coordinates of around (0.27, 0.71), (0.26, 0.72), and (0.15, 0.04), respectively.
在 200°C 和 pH=8 的条件下，将 Lu(NO)和 NaWO·2HO 进行水热反应，生成了新的化合物 NaLuWO·2HO。通过 Rietveld 技术对其进行分析，该化合物在正交晶系（空间群：Cmmm）中结晶，晶胞参数为 a=21.655(1)、b=5.1352(3)、c=3.6320(2) Å 和晶胞体积 V=403.87(4) Å。晶体结构呈现出-(NaO)-(NaO)-和-(LuO(HO)WO)-(LuO(HO)WO)-交替层，由 NaO 八面体和 WO 三角双锥公用的 O 离子连接在一起。通过在 600°C 下煅烧其 NaLuWO·2HO 类似物前体 2 小时，直接制备出四方结构且相纯的 Na(LuLnYb)(WO)荧光粉（Ln=Ho、Er 和 Tm），并对其下转换/上转换（DC/UC）光致发光进行了详细研究。结果表明，UC 发光主要由 Ho 的 650nm 左右的红光带（F→I 跃迁）、Er 的 500-575nm 左右的绿光带（H/S→I 跃迁）和 Tm 的 476nm 左右的蓝光带（G→H 跃迁）组成，均通过三光子过程实现。荧光粉的 DC 发光以 Ho 的 545nm 绿光发射（F/S→I 跃迁，λ=453nm）、Er 的 500-575nm 绿光发射（H/S→I 跃迁，λ=380nm）和 Tm 的 455nm 蓝光发射（D→F 跃迁，λ=360nm）为特征，其 CIE 色度坐标分别约为（0.27，0.71）、（0.26，0.72）和（0.15，0.04）。
