Adding both La3+and Co3+was used to tune the microstructure and electrical properties of Bi Fe O3(BFO) thin films, and Bi1-xLaxFe0.90Co0.10O3 thin films were grown on the Sr Ru O3-buffered Pt-coated silicon substrates by a radio frequency sputtering. A polycrystalline structure with(110) orientation was shown in thin films, and their resistivity dramatically increases as the La3+content increases. Their dielectric constant increases,and dielectric loss decreases with increasing La3+content.In addition, their ferroelectric and fatigue properties were enhanced with rising La3+content. The thin films with x = 0.03 have optimum electrical properties(e.g., remanent polarization 2Pr* 175.6 l C/cm2, coercive field2Ec* 699.5 k V/mm, dielectric constant er* 257 and tan d * 0.038), together with a good fatigue behavior. The impendence analysis of the films was conducted to identify the defects type during conductivity, and both hopping electrons and single-charged oxygen vacancies are mainly responsible for the conduction of grain and grain boundaries regardless of La3+content. As a result, the doping with both La3+and Co3+benefits the improvement in the electrical properties of BFO thin films.
