Leakage current and ferroelectric memory in Nd and Sm substituted Bi4Ti3O12 films
2005; Volume: 36; Issue: 3-6 Linguagem: Inglês
10.1016/j.mejo.2005.02.088
ISSN0026-2692
AutoresM. S. Tomar, R. E. Melgarejo, Surinder P. Singh,
Tópico(s)Photorefractive and Nonlinear Optics
ResumoLeakage current in ferroelectric devices is important because it affects the saturation. Rare earth substituted bismuth titanate (Bi4Ti3O12) electroceramics has emerged as new material system for non-volatile ferroelectric memory. We synthesized Bi4−xMxTi3O12 (M=Nd, Sm) for different compositions by sol–gel process and thin films were deposited by spin coating on Pt (Pt/TiO2/SiO2/Si) substrate. Room temperature leakage current and ferroelectric response was investigated on Pt/film/Pt capacitor structure. Ferroelectric response and leakage current density for different compositions are presented. Nd and Sm substituted thin films shows ferroelectric polarization (Pr) >50 and 18 μC/cm2, respectively, and leakage current densities about 10−7 A/cm2. Large polarization in rare earth substituted Bi4Ti3O12 layered perovskites is attributed to the dipole formation which tilts TiO6 octahedra to Bi2O2 interlayer of the unit cell.
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