Improved Ferroelectric and Fatigue Behavior of Bi0.95Gd0.05FeO3/BiFe0.95Mn0.05O3 Bilayered Thin Films

Bi0.95Gd0.05FeO3/BiFe0.95Mn0.05O3 (BGFO/BFMO) bilayered thin films with different thickness ratios of BGFO and BFMO layers were deposited in situ on SrRuO3-buffered Pt/TiO2/SiO2/Si(100) substrates by off-axis radio frequency magnetic sputtering, where a highly (110) orientation was developed. Their leakage currents and dielectric loss decrease dramatically due to the introduction of the highly resistive bottom BFMO layer, which promotes the texture development of the top BGFO layer by refining the grain cluster structure in the bilayered structure. The BGFO/BFMO bilayered thin film with the thickness fraction of similar to 1:1 exhibits a larger remanent polarization and improved fatigue endurance as compared to those of other film compositions, where an almost fatigue-free behavior was observed up to 10(10) switching cycles.