Structure of metal oxide multilayers deposited by sol-gel method on surface of NiTi shape memory alloy

The metal oxide layers were deposited onto the surface of NiTi shape memory alloy using sol-gel method. Single-, double- and triple-layers were obtained from a colloidal solution containing the precursor of zirconium tetrabutoxide and titanium tetrabutoxide, and annealed at 300°C for 1 h in argon. Phase composition was determined by grazing incidence X-ray diffraction. Surface roughness of the metal oxide layers were determined by atomic force microscopy. Surface morphology and thickness of the obtained layers were studied by scanning electron microscopy. It was found that all obtained layers revealed a composite structure, and were characterized by low surface roughness and thickness parameters. A homogeneous structure of the metal oxide layers deposited onto the surface of the medical NiTi alloy was ascertained only for double- and triple-layers.