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• 作者：Sebastian Schmiechen ; Hajnalka Schneider ; Peter Wagatha ; Cora Hecht ; Peter J. Schmidt ; Wolfgang Schnick
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：April 22, 2014
• 年：2014
• 卷：26
• 期：8
• 页码：2712-2719
• 全文大小：353K
• 年卷期：v.26,no.8(April 22, 2014)
• ISSN：1520-5002

文摘

The isotypic compounds M[Mg₃SiN₄] (M = Ca,Sr,Eu) have been synthesized by solid-state reactions in sealed tantalum ampules or in a radio-frequency furnace. The nitridomagnesosilicates crystallize in space group I4₁/a (No. 88). Crystal structures were solved and refined from single-crystal X-ray diffraction data (Z = 16, Ca[Mg₃SiN₄]:Ce³⁺, a = 11.424(2), c = 13.445(3) 脜, R1 = 0.040, wR2 = 0.106; Sr[Mg₃SiN₄]:Eu²⁺, a = 11.495(2), c = 13.512(3) 脜, R1 = 0.036, wR2 = 0.102; Eu[Mg₃SiN₄], a = 11.511(4), c = 13.552(4) 脜, R1 = 0.016, wR2 = 0.039). The nitridomagnesosilicates are isotypic to Na[Li₃SiO₄], containing a condensed tetrahedra network with a high degree of condensation (i.e., atomic ratio (Mg,Si):N) 魏 = 1. The crystal structures were confirmed by Rietveld refinement, lattice energy (MAPLE) calculations, and further investigated by ²⁹Si-MAS NMR. Ce³⁺-doped samples of Ca[Mg₃SiN₄] show yellow emission (位_max = 530 and 585 nm, fwhm 3900 cm^鈥? (130 nm)), while Sr[Mg₃SiN₄]:Eu²⁺ exhibits red luminescence (位_max = 615 nm) with the most narrow red emission of Eu²⁺-phosphors reported in the literature so far (fwhm 1170 cm^鈥? (43 nm)). According to this outstanding narrow red emission, originating from parity allowed 4f⁶5d¹ 鈫?4f⁷ transition in Eu²⁺, Sr[Mg₃SiN₄]:Eu²⁺ may point the way to the next generation red phosphor materials for application in illumination-grade white pc-LEDs.