Effect of (Bi, La)(Fe, Zn)O3 thickness on the microstructure and multiferroic properties of BiFeO3 thin films

The effect of Bi0.90La0.10Fe0.90Zn0.10O3 (BLFZO) thicknesses on the microstructure and multiferroic properties of BiFeO3 (BFO) thin films was investigated, and all bilayered thin films were grown on Pt-coated silicon substrates without any buffer layers by a radio frequency sputtering. A (110) orientation is dominant in all the bilayers, and two grain growth modes are identified in these bilayers by using an atomic force microscope, where different grain growth modes significantly affect their leakage behavior. The dielectric constant (epsilon(r)) of bilayers gradually increases, and magnetic properties were deteriorated with the addition of BLFZO with a higher epsilon(r) and a weaker magnetic behavior. An enhanced ferroelectric behavior of 2P(r) similar to 116.2 mu C/cm(2) and 2E(c) similar to 524 kV/cm could be observed in the BFO/BLFZO bilayered thin film with 80 nm BLFZO layer owing to a higher orientation degree of (110) and an interface coupling together with a lower leakage current density. As a result, electrical properties of BFO could be tailored by modifying the thicknesses of BLFZO. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4764340]