Effects of LaNiO3 bottom electrode on structural and dielectric properties of CaCu3Ti4O12 films fabricated by sol-gel method

CaCu3Ti4O12 (CCTO) thin films are prepared by a sol-gel method on LaNiO3-coated silicon and Pt/TiO2/SiO2/Si substrate. Compared with the films on Pt, the CCTO on LaNiO3 exhibits a (400) orientation. Dielectric loss of CCTO on LaNiO3 is lower than 0.25 within 100 Hz-10 kHz, lower than the reported value of CCTO grown on Pt/TiO2/SiO2/Si by pulse laser deposition. Possible reason is that LaNiO3 acts as seed layer for the growth of CCTO. The crystallinity of CCTO is improved and the dielectric properties are enhanced. Complex impedance spectrum of CCTO on LaNiO3 is discussed according to grain boundary barrier layer capacitance model. (c) 2008 American Institute of Physics.