Influence of Al3+ dopant on structure and infrared emission properties of Er3+:Ca3NbGa3Si2O14 crystalline powder

A series of 1.0 at.% Er3+ doped Ca3Nb(Ga1-x,Al-x)(3)Si2O14 (CNGAS) powders with different Al3+ content (x = 0-0.7) were prepared through high-temperature solid-state reaction. The effect of replacing Ga3+ by Al3+ on the lattice structure evolution and the emission transition I-4(13/2) -> I-4(15/2) of Er3+ were investigated in detail based on the X-ray powder diffractions, Rietveld refinements, fluorescence spectra and decay curves. It reveals that the Al3+ content in the range of 0-0.5 has little impact on structural integrity and degree of order of the Ca3NbGa3Si2O14 (CNGS) lattice, The Er3+:CNGAS with Al3+ substitution (x = 0.5) exhibits even enhanced fluorescence emission rather than that of the Er3+:CNGS. The results indicates that the strategy of Al3+ substitution is cost-saving and feasible, and Er3+ activated Ca3Nb(Ga0.5Al0.5)(3)Si2O14 crystal as a promising 1.55 mu m laser gain medium would be comparable to that of the CNGS crystal.