Fabrication of lanthanum manganese oxide thin films on yttria-stabilized zirconia substrates by a chemically modified alkoxide method

Perovskite-type thin films of lanthanum manganese oxide (LaMnO3) were prepa red on yttria (8%) stabilized zirconia substrate by the sol-gel process fro m an alkoxide solution of lanthanum isopropoxide (La(O-i-C3H7)(3)) and mang anese isopropoxide (Mn(O-i-C3H7)(2)). The alkoxide solution was chelated wi th 2-ethyacetoacetate, and further modified with polyethylene glycol (PEG). The obtained LaMnO3 thin film was transparent and macroscopically crackles s. X-ray diffraction, differential thermal analysis-thermogravimetry analys is, and scanning electron microscope observations indicated that single-pha se LaMnO3 thin films with a grain size of 80 to 100 mn are formed when a sp in-coated LaMnO3 gelled film is heated at 600 degreesC for I h. The porous and homogeneous grain structure with a grain size of < 100 nm can be obtain ed when the LaMnO3 gelled film is heated at 600 degrees and 800 degreesC. I t was considered that PEG might accelerate the crystallization of the perov skite phase, which indicates that PEG assists the formation of the La-O-Mn frame network during partial hydrolysis and condensation reactions in sol-g el processes.