Effect of annealing on the electrochemical properties of the Li–Mn–O thin films, prepared by high frequency RF magnetron sputtering

Li–Mn–O films are deposited by RF magnetron sputtering using 27.12 MHz as the excitation frequency. The sputtering rate of deposition is found to be higher than the one with conventional sputtering frequency. The rate of deposition as high as 42 Å/min has been achieved using this frequency. The X-ray diffraction patterns of films annealed in air show a gradual increase in crystallinity with the increase in annealing temperature. The electrochemical studies reveal that the films annealed at 700 °C show the best results in terms of crystallinity as well as discharge capacity. It is evident from this investigation that the higher excitation frequency magnetron discharge enhances the nucleation, and there by the rate of sputtering. This can be due to the reduced dc voltage appearing at the target surface at higher excitation frequency, which reduces the unnecessary ion bombardment of the growing film.

► Li–Mn–O films are deposited by RF magnetron sputtering using 27.12 MHz.
► The rate of deposition as high as 42 Å/min has been achieved using this frequency.
► The effect of post annealing on the electrochemical properties of Li–Mn–O films are studied.
► As the annealing temperature increases, the crystallinity and discharge capacity of the films also increases.
► Films annealed at 700 °C show the best results in terms of crystallinity as well as discharge capacity.