Synthesis and Photoluminescence Properties of Eu 3+ ‐Doped Calcium Phosphates

Eu 3+ ‐doped (1–12 mol%) calcium hydroxyapatite (HA) and β‐tricalcium phosphate (β‐TCP) powders were synthesized by a precipitation method and their photoluminescence (PL) properties were investigated. Eu has a limited solubility in HA and Eu 2 O 3 was detected by X‐ray diffraction above 3% doping, whereas a nearly single β‐phase was obtained up to 6% doping in TCP but EuPO 4 appeared in the 12% Eu‐doped specimen. Electron spin resonance measurement confirmed that europium ions exist as Eu 3+ in both samples. Eu 3+ ‐doped HA exhibited a strong emission at 575 nm with several minor peaks at 610–640 nm and Eu 3+ ‐doped TCP had an intense emission at 613 nm with secondary peaks at 590–600 nm, which were consistent with the earlier reports determined at low temperatures. In Eu‐doped TCP, the PL intensity increased with increasing calcination temperature without phase transformation. The more the Eu added, the higher the PL intensity obtained in both cases.