MOCVD of YSZ coatings using β-diketonate precursors

Metallorganic chemical vapor deposition (MOCVD) was investigated as a more efficient means to fabricate yttria-stabilized zirconia (YSZ) for thermal barrier coating. The MOCVD precursors were Y(tmhd)3 and Zr(tmhd)4 (tmhd, 2,2,6,6-tetramethyl-3,5-heptanedianato) and delivered via aerosol-assisted liquid delivery (AALD). The maximum YSZ coating rate was 14.2 ± 1.3 μm h−1 at 827 °C yielding a layered coating microstructure. The growth was first-order with temperature below 827 °C with an apparent activation energy of 50.9 ± 4.3 kJ mol−1. Coating efficiency was a maximum of approximately 10% at the highest growth rate. While homogeneous nucleation remained a problem, the deposition of YSZ with only minor carbon content was achieved.