An innovative technique to simply fabricate ZrO2–HA–TiO2 nanostructured layers

For the first time, ZrO2–HA–TiO2 layers were synthesized through EPD-Enhanced MAO (EEMAO) technique in only one step where no supplementary treatment was required. SEM, XRD, EDX, and XPS techniques were employed to propose a correlation between the growth parameters and the physical and chemical properties of the layers. The layers revealed a porous structure where applying higher voltages and/or utilizing higher concentrated electrolytes resulted in formation of wider pores and increasing the zirconium concentration in the layers; meanwhile, prolonging the growth time had the same effects. The layers mainly consisted of anatase, hydroxyapatite, monoclinic ZrO2, and tetragonal ZrO2 phases. Increasing the voltage, electrolyte concentration, and time, hydroxyapatite as well as tetragonal ZrO2 was decomposed to α-TCP, monoclinic ZrO2, and ZrO. The nanosized zirconia particles (d = 20–60 nm) were further accumulated on the vicinity of the layers when thicker electrolytes were utilized or higher voltages were applied. Emphasizing on the chemical and electrochemical foundations, a probable formation mechanism was finally put forward.