Role of chemical composition of oxide layer on stainless steel for ZrO2 coating by hydrothermal process

Thin films of ZrO2 have been developed by hydrothermal process on pre-oxidized stainless steel (SS) surfaces composed of different oxides like spinels or α-Fe2O3. Variations in thicknesses and uniformity of ZrO2 films have been observed on different pre-oxidized SS surfaces. Raman scattering spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and X-ray diffraction techniques have been used to explain mechanisms of formation of ZrO2 films on various pre-oxidized SS surfaces. A pre-oxidized layer of α-Fe2O3 seems to be an ideal oxide on the SS surface for uniform coating of ZrO2. This may be attributed to close match of lattice parameters of ZrO2 with that of α-Fe2O3.