Nd diffusion in YAG ceramics

Neodymium diffusion was observed in yttrium aluminum garnet (YAG) polycrystals with negligible change of microstructure during diffusion. Ceramic bi-layer samples were fabricated via a technique developed for ceramic laser amplifiers, from flame-spray pyrolized powders of un-doped YAG and 1% Nd:YAG. Diffusion studies were carried out on these samples at temperatures lower than the sintering temperature, such that average grain diameter remained approximately 0.8μm for all samples. Effective diffusivity was 117±4m2/sexp623±70kJ/molKRT for temperatures between 1500 and 1600 °C and with 1.2 ± 0.3 grain boundaries per micrometer.

Research highlights
► Following 4 min of sintering at 1700 °C Nd:YAG ceramic diffusion couples displayed negligible grain growth after up to 64 h at 1600.
► Stable microstructure allows for controlled dopant diffusion.
► Effective diffusivity of Nd in polycrystalline YAG with 1:2 ± 0:3 grain boundaries per micrometer is 117±4m2/sexp623±70kJ/molKRT.