Xinjian Bao, Xiaoyang Liu, Xi Liu
Oct 26, 2017
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Influential Citations
2
Citations
Journal
RSC Advances
Abstract
The crystal properties of a terbium silicate Na2Tb1.08Ca2.92Si6O18H0.8 synthesized at 1 GPa and 800 °C using a piston-cylinder apparatus is reported. Our single-crystal X-ray analysis shows that this new compound is triclinic with the space group 1 (Z = 1), and its unit-cell parameters are a = 7.056(3) A, b = 7.075(3) A, c = 8.029(3) A, α = 102.381(5)°, β = 95.387(6)°, γ = 90.552(6)°, and V = 389.6(2) A3. This structure consists of octahedral double chains of the compositions [Ca0.875Tb0.125O6] and [Ca0.585Tb0.415O6]. The double chains are linked by tetrasilicate chains via vertex oxygen atoms to form a 3D framework with 6-membered (2 octahedra and 4 tetrahedra) ring channels along the b-axis where the Na+ cations locate. The luminescence properties of the Na2Tb1.08Ca2.92Si6O18H0.8 phase are also investigated. This phase, with most of its Tb in 3+, emits mainly from one transition, 5D4 → 7F5 (542 and 552 nm). The room temperature fluorescence decay curves are fit well by an exponential function, yielding a lifetime value of about 2.498(7) ms.