Time-resolved fluorescence line-narrowing of Eu3+ in biocompatible eutectic glass-ceramics

The spectroscopic properties of Eu3+ in biocompatible glass and glass-ceramic eutectic rods of composition 0.8CaSiO3-0.2Ca3(PO4)2 doped with 0.5 wt% of Eu2O3 are investigated to explore their potential applications as optical probes. The samples were obtained by the laser floating zone technique. Depending on the growth rate, they exhibit three (two crystalline and one amorphous) or two (one crystalline and one amorphous) phases. The crystalline phases correspond to Ca2SiO4 and apatite-like structures. At high growth rates the system presents an amorphous arrangement which gives a glass phase. The results of time-resolved fluorescence line narrowing spectroscopy obtained under excitation within the inhomogeneous broadened 7F0→5D0 absorption band allow to isolate the emission from Eu3+ ions in the crystalline and amorphous environments and to accurately correlate the spectroscopic properties with the microstructure of these eutectics.