Blue and red dual emission nanophosphor CaMgSi2O6:Eun+; crystal structure and electronic configuration

Well dispersed Eu doped CaMgSi2O6 (CMS) nanoparticles of 12–19 nm average sizes were synthesized by the co-precipitation method using different ratios of water and ethanol mixture as a solvent and subsequent air annealing. While ethanol as solvent produced pure CMS in monoclinic phase, pure water produced Ca2MgSi2O7 (C2MS) and CMS in the mixed phase. Apart from the composition of CMS and C2MS, concentration and ionization state of the activator depended strongly on the composition (effective dielectric constant) of the solvent. Both the blue and red emission bands could be revealed for the europium activated CMS nanoparticles using single europium precursor. Efficiency of blue and red emissions in the nanophosphors, controlled by the relative abundance of europium in Eu2+ and Eu3+ oxidation states, could be controlled by adjusting the water content in the solvent. The relative intensity of the red emission (615 nm) decreased with the increase of water content in the solvent.