Influence of doping concentration on microstructure evolution and sintering kinetics of Er:YAG transparent ceramics

Abstract Erbium doped yttrium aluminum garnet (Er:YAG) transparent ceramics with different Er doping concentrations were fabricated from powder mixtures of α-Al 2 O 3 , Y 2 O 3 , and Er 2 O 3 with tetraethoxysilane (TEOS) and MgO as sintering aids by solid-state reactive sintering. The sintering temperatures were from 1500 °C up to 1750 °C. Densification, microstructure evolution and optical transparency of Er:YAG ceramics with different doping concentrations were examined. For all the doping concentration, fully dense Er:YAG transparent ceramics with homogeneous grain size distributions around 20–23 μm were obtained by sintering at 1750 °C for 50 h, whose transmittances were all above 83% at the wavelength of 1200 nm. The grain growth kinetic of Er:YAG ceramics was also investigated as a function of erbium content. The calculated activation energies for grain growth of the 0.5, 1.0, 5.0, and 10 at%Er:YAG ceramics were 779, 855, 805, and 861 kJ/mol, respectively. The luminescence spectra were also measured and discussed.