Periodicity dependence of the ferroelectric properties in BiFeO3∕SrTiO3 multiferroic superlattices

R. Ranjith (1) , B. Kundys (1) , Wilfrid Prellier (1)

1 CRISMAT - Laboratoire de cristallographie et sciences des matériaux

Artificial superlattices of (BiFeO3)m(SrTiO3)m (m=1–10 unit cells) consisting of multiferroic BiFeO3 and insulating SrTiO3 layers were fabricated on (100)-oriented SrTiO3 substrates by pulsed laser ablation. The remnant polarization and leakage current behavior of these films were studied by varying the periodicity (8–80Å) of the superlattice. Compared to single layer BiFeO3 thin films, the leakage current was reduced by a few orders of magnitude on increasing the periodicity. Reduced leakage and intrinsic polarization hysteresis were observed and confirmed by pulsed polarization analysis for all periodicities (∼20–60Å) . The leakage current was dominated by space charge limited conduction. This work was carried out in the frame of the NoE FAME (FP6-5001159-1), the STREP MaCoMuFi (NMP3-CT-2006-033221), and the STREP CoMePhS (NMP4-CT-2005-517039) supported by the European Community and by the CNRS, France. Partial support from the ANR (NT05-1-45177 and NT05-3-41793) is also acknowledged. The authors would also like to acknowledge Dr. L. Mechin, C. Fur, J. Lecourt, Professor G. Poullain, Dr. Ch. Simon, and Dr. W. C. Sheets.

Domains: Physics [physics]; Chemical Sciences; Chemical Sciences; Material chemistry

R. Ranjith, B. Kundys, Wilfrid Prellier. Periodicity dependence of the ferroelectric properties in BiFeO3∕SrTiO3 multiferroic superlattices. Applied Physics Letters, 2007, 91 (22), pp.222904. ⟨10.1063/1.2817933⟩. ⟨hal-03545077⟩