This paper discusses the preparation and characterization of sol‐gel produced thin films for barrier layer and high Tcsuperconductor applications. Hydrolyzed metal alkoxide solutions were spin coated on Si substrates with subsequent thermal processing. Barrier layers of alkaline earth oxides, perovskites, Y2O3, ZrO2and others were produced. Characterization was performed via SEM, XRD, ESCA, Auger depth profiling and four point probe resistivity measurements for 1‐2‐3 thin films. On Si wafers, barrier layer films were fairly smooth with some cracking and pitting present. Si migration was severe for alkaline earth thin films on Si wafers. Some perovskite films on Si showed formation of Ba‐Si‐O phases at the Si interface.Thin films of 1‐2‐3 on sol‐gel produced barrier layers of SrTiO3or ZrO2on Si showed Ba pileup at the Si interface and were not superconducting. 1‐2‐3 layers deposited on single crystal ZrO2were superconducting and showed onset temperatures of 90 K with zero resistance reached at about 55 K. SEM morphology differences were observed for the different 1‐2‐3 preparations.