Eu as the structural probe in the phase transformation of CMSA by site-selective occupancy and adjustable multimode white luminescence in Ca(MgAl)(SiAlO) akermanite based on high-aluminum blast furnace slag

• Published in: Dalton transactions : an international journal of inorganic chemistry 2022-09, Vol.51 (35), p.1331-1331
• Main Authors: Cao, Fabin, Xiong, Ying, Liu, Jian, Zhang, Jingwen, Qin, Kailong, Sun, Jingbo, Liu, Weiming, Shen, Xingmei, Wu, Xingrong, Wu, Zhaojin
• Format: Article
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d2dt01532c

A tunable multimode white emission Ca 2 (Mg 0.5 Al 0.5 )(Si 1.5 Al 0.5 O 7 ):Eu 2+ /Eu 3+ phosphor was prepared by doping Eu 2 O 3 in molten high-aluminum blast furnace slag. The structural probe Eu 2+ was studied during phase transformation between the glassy state and Ca 2 (Mg 0.5 Al 0.5 )(Si 1.5 Al 0.5 O 7 ) crystals based on site-selective Eu 2+ occupancy. When the doped Eu 2+ ions occupied two different Ca 2+ sites in the matrix, blue light (421 nm) and green light (516 nm) emissions were observed corresponding to two types of Eu 2+ Ca 2+ , namely Eu 2+ Ca 2+ (Mg 2+ → Al 3+ ) and Eu 2+ Ca 2+ (Si 4+ → Al 3+ ). The effects of Eu concentration (0.1-2.0 mol%), heat treatment temperature (800-1000 °C), and thermal quenching temperature (30-150 °C) on the structural evolution of the emission unit were studied by differential scanning calorimetry (DSC), photoluminescence spectroscopy (PL) and X-ray diffraction (XRD) analyses. The Eu 2+ Ca 2+ (Mg 2+ → Al 3+ ) structure formed by site-selective Eu 2+ occupancy possessed better structural stability in the Ca 2 (Mg 0.5 Al 0.5 )(Si 1.5 Al 0.5 O 7 ) crystal matrix, in favour of light-emitting diode (LED) illumination and plasma display panels (PDPs). The (Mg 2+ → Al 3+ )O 4 tetrahedron expansion causes Eu 2+ emission blue shift and the (Si 4+ → Al 3+ )O 4 tetrahedron shrinkage gives Eu 2+ emission red shift. So structural probe of Eu 2+ was explored by Eu 2+ site-selective occupancy in akermanite.