Tunable photoluminescence of apatite phosphor Ca _{5.95− x} Sr _x La ₄ (SiO ₄ ) ₂ (PO ₄ ) ₄ O ₂ :0.05Eu ²⁺ and its application in light‐emitting diodes

A series of new apatite phosphors Ca 5.95− x Sr x La 4 (SiO 4 ) 2 (PO 4 ) 4 O 2 :0.05Eu 2+ ( x = 0‐5.95) were prepared with the solid‐state method. The variations of the occupation rate and cell parameters were investigated in detail, demonstrating that the phosphors are pure phases and that the different occupation rates of La 3+ , Ca 2+ , and Sr 2+ ions are due to the different electrostatic bond strengths. The reflectance and...