Fabrication, microstructure and optical properties of titanium doped YAG transparent ceramic

Highly transparent titanium doped Y3Al5O12 (YAG) ceramic for the first time was fabricated by solid-state reaction method, which was sintered at 1770 °C for 10 h under the vacuum condition. The transmittance of the sample reached as high as 80% in the infrared region. The microstructure and the optical properties of the ceramics varied obviously with three different annealing conditions: in air, under vacuum, and in both air and then under vacuum, and these three kinds of ceramics were named as: Sample A, Sample B, and Sample C in sequence. There existed numerous impurity phases in both Sample B and Sample C, which were experimentally speculated as Al2O3 and Y2Ti2O7. Only the Sample A kept no any other phase or pore and displayed uniform grains. Furthermore, three absorption peaks of Sample A at about 400, 498 and 586 nm all coexisted with the Ti3+ ion and disappeared as soon as the ceramic was treated in air. The X-ray fluorescence of Sample B showed a peak at about 500 nm, but Sample A showed no peak. The intense photoluminescence peaks at about 775 and 810 nm of the ceramic excited by 532 nm laser diode system may demonstrate that Ti:YAG ceramic could be a promising laser material.