CHEMICAL BEHAVIOR OF ZIRCONIUM OXYCHLORIDE OCTAHYDRATE AND ACETIC-ACID IN PRECURSOR SOLUTION FOR ZIRCONIA FILM FORMATION ON GLASS

Precursor solutions for zirconia films on soda lime silica glass subst rate were prepared from zirconium oxychloride octahydrate (ZOO) and ac etic acid (HOAC) maintaining the mol ratios, [HOAC]/[ZOO] = 2, 4, 6, 8 and 10. A characteristic UV absorption band at similar to 280 nm in t he similar to 120 h aged precursor solutions was identified for acetat e group of the zirconium acetato complexed species. The presence of ac etate ligand coordinated with either ZrOOH+ or [Zr-4(OH)(8)](8+) Or Wi th both was predicted by the studies of UV spectra of aged solutions a nd FTIR spectra of unbaked films on silicon wafer. Dipping technique w as followed for film formation. Thicknesses and refractive indices of the baked (450 degrees +/- 5 degrees C) films were in the ranges 1818 +/- 20 Angstrom and 1.702-1.762 respectively. The positive SIMS experi ment on two typical films baked at 450 degrees +/- 5 degrees C derived from the precursors with [HOAC]/[ZOO] = 2 and 6, detected the ionic s pecies, Zr+, ZrO+, ZrO2+, Na+, Ca+, Fe+, H+ while the negative SIMS de tected O- and Cl-. The relative contents of the ionic species with res pect to Zr+ were dependent on the acid content of the precursors. Refl ection (%) of the baked films in the UV region was also dependent on t he acid content of the precursors. Electron diffraction pattern of the typical baked film derived from the precursor with [HOAC]/[ZOO] = 2 e xhibited meta-stable cubic phase of zirconia and the grains were found to be elongated (aspect ratio, 2.00-2.33).