Linear structural evolution induced tunable photoluminescence in clinopyroxene solid-solution phosphors

Clinopyroxenes along the Jervisite (NaScSi2O6)-Diopside (CaMgSi2O6) join have been studied, and a solid-solution of the type (Na(1-x)Ca(x))(Sc(1-x)Mg(x))Si2O6 has been identified in the full range of 0 ≤ x ≤ 1. The powder X-ray patterns of all the phases indicate a structural similarity to the end compounds and show smooth variation of structural parameters with composition. The linear structural evolution of iso-structural (Na(1-x)Ca(x))(Sc(1-x)Mg(x))Si2O6 solid-solutions obeying Vegard's rule has also been examined and verified by high resolution transmission electron microscopy (HRTEM). The continuous solid-solutions show the same structural type, therefore the photoluminescence spectra of Eu(2+) doped samples possess the superposition of spectral features from blue-emitting component (CaMgSi2O6:Eu(2+)) and yellow-emitting one (NaScSi2O6:Eu(2+)). This indicates that the spectroscopic properties of (Na(1-x)Ca(x))(Sc(1-x)Mg(x))Si2O6 clinopyroxene solid-solutions are in direct relations with structural parameters, and it is helpful for designing color-tunable photoluminescence with predetermined parameters.