The Korean Society of Surface Science and Engineering

In this study, pure (K_0.5Na_0.5)NbO₃ and Mn-substituted (K_0.5Na_0.5)(Nb_0.995Mn_0.005)O₃ thin films were manufactured using the sol-gel method, which can easily and inexpensively produce various thin films on a large area, and their surface structures were compared and analyzed. Although it is not easy to synthesize a group 5 transition metal and an alkali metal to produce a thin film due to the difference in chemical properties of the two elements, pure (K_0.5Na_0.5)NbO₃ thin films and (K_0.5Na_0.5)(Nb_0.995Mn_0.005)O₃ nanocrystal thin films were obtained by substituting a small amount of Mn. The effect of Mn on the change in the microstructure of pure (K_0.5Na_0.5)NbO₃ and Mn-substituted (K_0.5Na_0.5)(Nb_0.995Mn_0.005)O₃ was analyzed, and the effect on the change in surface roughness was analyzed. As a specific experimental result that Mn substitution controls the surface properties of (K_0.5Na_0.5)NbO₃, it was examined that Mn increases the chemical stability of (K_0.5Na_0.5)NbO₃, and thus the increase in resistance to surface oxidation reaction is related to the decrease in surface roughness. Furthermore, X-ray diffraction analysis confirmed that the Mn-substituted (K_0.5Na_0.5)(Nb_0.995Mn_0.005)O₃ thin film formed a stable perovskite phase with c-axis orientation. Thin films of both compositions heat-treated at 700°C for 1 h in an air atmosphere were analyzed for surface morphology and grain size using scanning electron microscopy and atomic force microscopy. The deposition thickness, average particle size, and root mean square roughness of pure (K_0.5Na_0.5)NbO₃ and (K_0.5Na_0.5)(Nb_0.995Mn_0.005)O₃ thin films were analyzed to be 411 nm and 413 nm, 148 nm and 151 nm, and 17.14 nm and 15.08 nm, respectively.

키워드 (K_0.5Na_0.5)NbO₃; (K_0.5Na_0.5)(Nb_0.995Mn_0.005)O₃; Sol-gel method; Thin film.