Fabrication and laser operation of Yb:Lu₂O₃ transparent ceramics from co‐precipitated nano‐powders

Abstract

In this article, 5 at.% Yb:Lu2O3 transparent ceramics were fabricated by vacuum sintering combined with hot isostatic pressing (HIP) posttreatment using co‐precipitated nano‐powders. The influence of precipitant molar ratio, ammonium hydrogen carbonate, to metal ions (AHC/M3+, R value) on the properties of Yb:Lu2O3 precursors and calcined powders was investigated systematically. It was found that the powders with different R value calcined at 1100°C for 4 hours were pure cubic Lu2O3 but the morphologies of precursors and powders behaved differently. The opaque samples pre‐sintered at 1500°C for 2 hours grew into transparent ceramics after HIP posttreatment at 1750°C for 1 hour. The final ceramic with R = 4.8 showed the best optical quality with the in‐line transmittance of 79.7% at 1100 nm. The quasi‐CW laser operation was performed at 1034 nm and 1080 nm with a maximum output power up to 8.15 W as well as a corresponding slope efficiency of 58.4%.

Fabrication, microstructures, and optical properties of Yb:Lu2O3 laser ceramics from co-precipitated nano-powders

“…Briefly, the optical quality of 5 at% Yb:Lu 2 O 3 ceramics is improved especially in the short wavelength range compared with the results reported in Ref. [27].…”

“…Figure 5 shows the FESEM micrographs of (a) the prepared precursor and (b) calcined 5 at% Yb:Lu 2 O 3 nano-powder. It can be seen that the amorphous precursor consists of spherical nanogranules and shows weaker agglomeration compared to the flake structural precursors reported in our previous study [27]. The microstructure of the synthesized precursor changes greatly.…”

“…In our previous studies, we synthesized Yb:Lu 2 O 3 nano-powders in pure water solvent and investigated the influence of precipitants [27,28]. It can be seen that the resultant precursors exhibited flake structures, indicating that the dispersity of the precursors needs to be improved.…”

Synthesis of yttria nanopowder with poly acrylic acid as dispersant for highly transparent yttria ceramics

“…The existence of PAA does not affect the crystallite sizes of the powders but does affect the calcinated particle size slightly. As the formed particles are an agglomeration of the crystallites, Liu et al 21 had suggested to use a formula of N = (D BET /D XRD ) 3 to quantitatively describe the dispersity of the synthesized powders. The smaller the N value, the better the dispersity of the powder is.…”

“…Since addition of suitable amount of sulfate ions in the coprecipitation process could effectively produce yttria powders with low agglomeration and high sinterability, the method has been widely adopted. [17][18][19][20][21][22] Worth of mentioning that using coprecipitated nanopowders with sulfate ions as the dispersant, Liu et al 21 fabricated 5 at.% Yb:Lu 2 O 3 laser ceramics and achieved laser oscillation of the laser ceramics, Dai et al 19 reported the fabrication of 5 at.% Yb:Sc 2 O 3 laser ceramics, and Xie et al 22 fabricated 5 at.% Eu:Lu 2 O 3 transparent ceramics for X-ray detection. However, we note that there is a serious drawback of using sulfate ions as a dispersant.…”