Coatings of yttrium aluminum garnet (Y3Al5O12 YAG), which is a promising hi
gh-temperature ceramic, were developed for the first time using a novel pre
cursor plasma spraying (PPS) technique. The precursor sol was sprayed using
a radiofrequency induction plasma technique. X-ray diffraction analysis of
the as-sprayed coatings confirmed that a metastable hexagonal yttrium alum
inate (H-YAlO3) was the major phase. The above-described specimen, on furth
er treatment with plasma, was converted to cubic garnet (YAG) as the major
phase, with a minor amount or orthorhombic YAlO3 (O-YAP) phase. Al-27 magic
-angle spinning nuclear magnetic resonance of the YAG coating corroborated
the X-ray results and confirmed the presence of YAG and O-YAP phases. Forma
tion of the garnet phase through the PPS technique is proof that the chemis
try can be controlled in the plasma. This finding opens up new avenues for
developing complex functional oxide deposits.