The influence of acceptor doping on the structure and electrical properties of sol-gel derived BiFeO3 thin films

Bismuth Ferrite (BFO)films doped with strontium resulting in a nominal composition of Bi1-xSrxFe1O3 (x = 0-0.15) were fabricated using a sol-gel process on Pt/TiO2/SiO2/Si substrates by rapid thermal annealed in air at 700 degrees C. A decrease in the grain size (from 1 mu m to 90 nm) with increasing Sr concentration from 0 to 15% was observed, coupled with the degradation of columnar grain growth. X-ray diffraction and raman scattering showed evidence of a structural change from rhombohedral to pseudocubic with increasing Sr concentration. Leakage measurements revealed that films with Sr acceptor doping showed increased leakage compared to pure BFO, however the film leakage did not increase with increasing acceptor concentration due to microstructural modifications.