NOVELTY - A precursor solution (70) is injected to a thermal jet (60). Solvent is evaporated from the precursor solution, to form unpyrolyzed solid particles. Portion(s) of unpyrolyzed solid particles are pyrolyzed, to form pyrolyzed solid particles comprising yttrium aluminum garnet-based ceramic. Portion(s) of pyrolyzed solid particles are melted, to form droplets comprising yttrium aluminum garnet-based ceramic. The droplets comprising yttrium aluminum garnet-based ceramic are deposited on a substrate (100), to form thermal barrier coating (90).    USE - Formation of thermal barrier coating used for article in hot section of gas turbine, turbine blades, turbine vanes, turbine blade outer air seals, and combustor liner segments (all claimed). Uses include but are not limited to hot section components in gas turbine engines for jet aircraft and power generation, diesel engines, dielectric coatings, catalytic films, doped oxide films for use in fuel cells for gas separation and purification, electronic and ionic conductivity membranes, and sensor devices.    ADVANTAGE - The method provides thermal barrier coating with excellent thermal conductivity and strain tolerance.    DETAILED DESCRIPTION - A precursor solution is injected to a thermal jet. The precursor solution comprises metal ion precursors to yttrium aluminum garnet-based ceramic. Solvent is evaporated from the precursor solution, to form unpyrolyzed solid particles. Portion(s) of unpyrolyzed solid particles are pyrolyzed, to form pyrolyzed solid particles comprising yttrium aluminum garnet-based ceramic. Portion(s) of pyrolyzed solid particles are melted, to form droplets comprising yttrium aluminum garnet-based ceramic. The droplets comprising yttrium aluminum garnet-based ceramic are deposited on a substrate, to form thermal barrier coating. INDEPENDENT CLAIMS are included for the following:    (1) thermal barrier coating; and    (2) article.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of a solution precursor plasma spray process.    Solution precursor plasma spray system (10)    Thermal jet (60)    Precursor solution (70)    Thermal barrier coating (90)    Substrate (100)