Scaling laws in annealed LiCoOx films

The surface morphology evolution due to the annealing process of LiCoOx thin films deposited by rf sputtering is studied by means of an atomic force microscope. Linear relationships were observed in log-log plots of interface width versus window length, as predicted by scaling laws. For as-grown films, only one growth exponent ais evidenced. For annealed films two different slopes alpha(1) and alpha(2) were observed, indicating distinct growth dynamics in the system. The roughness exponent for the as-grown film and the internal morphology of the crystalline grains for the annealed films can be described by a diffusional process. The macrostructure shows characteristics of a Kardar-Parisi-Zhang system [M. Kardar, G. Parisi, Y. C. Zhang, Phys. Rev. Lett. 56, 889 (1986); J. Krim and G. Palasantzas, Int. J. Mod. Phys. B 9, 599 (1995)]. An activation energy E-d = (0.11 +/-0.01) eV is determined for the diffusion process. (C) 1999 American Institute of Physics. [S0003-6951(99)02212-3].