CaTiO3 films sputter-deposited under simultaneous Ti-ion implantation on Ti-substrate

The CaTiO3 films of 50 nm thick were prepared on Ti-substrate with and without simultaneous Ti+-implantation followed by annealing in air or in vacuo, and were characterized by using RBS, AES, XRD and XPS. Concentration of oxygen on the as-deposited specimens was higher and that of Ti lower in comparison with the chemical formula of CaTiO3. However, with increase of the accelerating voltage of Ti-implantation, Va, concentrations of O decreased and that of Ti increased. Annealing in air resulted in formation of Ti-oxide because of oxidation of Ti substrate. However, the degree of the oxidation decreased with increase in Va. Annealing in vacuo, however, changed a part of or full of CaTiO3 film to a Ca-oxide layer in the top surface region. On the other hand, annealing in air, three layers were formed, that is, a Ti-containing Ca-rich layer, a CaTiO3 layer, and a thick Ti-oxide layer, in an order from the surface. Immersion test in Hanksʹ solution suggested the surface coating with CaTiO3 and simultaneous Ti+-implantation followed by annealing in air will be better for good bone conductivity.