Effects of LaNi O3 bottom electrode on structural and dielectric properties of Ca Cu3 Ti4 O12 films fabricated by sol-gel method

Ca Cu3 Ti4 O12 (CCTO) thin films are prepared by a sol-gel method on LaNi O3 -coated silicon and PtTi O2 Si O2 Si substrate. Compared with the films on Pt, the CCTO on LaNi O3 exhibits a (400) orientation. Dielectric loss of CCTO on LaNi O3 is lower than 0.25 within 100 Hz-10 kHz, lower than the reported value of CCTO grown on PtTi O2 Si O2 Si by pulse laser deposition. Possible reason is that LaNi O3 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 LaNi O3 is discussed according to grain boundary barrier layer capacitance model.