Multiferroic and fatigue behavior of silicon-based bismuth ferrite sandwiched structure

Abstract

Sandwich structured (Bi0.92La0.08)(Fe 0.87Zn0.13)O3/(Bi0.92La 0.08)(Fe0.93Zn0.07)O3/(Bi 0.92La0.08)(Fe0.87Zn0.13)O 3 thin films were prepared on Pt/TiO2/SiO 2/Si(100) substrates by radio frequency sputtering. High (110) orientation is induced in these sandwiched structures due to the introduction of the bottom (Bi0.92La0.08)(Fe0.87Zn 0.13)O3 layer with a (110) orientation. The space-charge-limited current mechanism is identified to dominate the leakage behavior of these sandwiched structures, and the lowest leakage current density is well established in such a sandwiched structure with a thickness ratio of 1:1:1 owing to its denser microstructure. All sandwiched structures demonstrate good fatigue behavior at a switching cycle of ∼2.96 × 109 and similar saturated M-H loops with 2M ∼ 15.5 emu cm-3 due to the interface coupling among these constituent layers. The sandwiched structure with a thickness ratio of 1:1:1 possesses a better P-E loop with a high remanent polarization of 2Pr ∼ 142.6 μC cm-2 and a low coercive field of 2Ec ∼ 695.0 kV cm-1. As a result, the sandwiched structure is an effective way to improve the multiferroic and fatigue behavior of bismuth ferrite materials. © 2011 The Royal Society of Chemistry.