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.

A tunable multimode white emission Ca(MgAl)(SiAlO):Eu/Eu phosphor was prepared by doping EuO in molten high-aluminum blast furnace slag. The structural probe Eu was studied during phase transformation between the glassy state and Ca(MgAl)(SiAlO) crystals based on site-selective Eu occupancy. When the doped Eu ions occupied two different Ca sites in the matrix, blue light (421 nm) and green light (516 nm) emissions were observed corresponding to two types of Eu, namely Eu (Mg → Al) and Eu (Si → Al). 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 (Mg → Al) structure formed by site-selective Eu occupancy possessed better structural stability in the Ca(MgAl)(SiAlO) crystal matrix, in favour of light-emitting diode (LED) illumination and plasma display panels (PDPs).