Facile synthesis of cubic and spindle-shaped CaCO3 particles and their applications as red phosphor doped with Eu3+

Cubic and spindle-shaped CaCO3 particles were successfully prepared using carbonation method without any additional crystal controlling agent. The experimental results showed that carbonation temperature and initial concentration of Ca(OH)2 slurry are the main factors to influence the morphology of CaCO3 particles. The as-prepared cubic and spindle-shaped CaCO3:Eu3+ particles are pure calcite, and Eu3+ ions have been effectively doped into the cubic and spindle-shaped CaCO3 lattices. Without any post-treatment such as sintering, both cubic and spindle-shaped CaCO3:Eu3+ particles exhibit strong red emission corresponding to the 5D0–7F2 transition of the Eu3+ ions under UV light excitation. Furthermore, CaCO3:Eu3+ cubic particles show higher luminescence intensity than CaCO3:Eu3+ spindle-shaped particles due to fewer defects of cubic CaCO3 particles.