Ferroelectric properties and leakage current characteristics of radio-frequency-sputtered SrBi2(V0.1Nb0.9)2O9 thin films

The ferroelectric properties and leakage current mechanisms of polycrystalline SrBi2(V0.1Nb0.9)(2)O-9(SBVN) thin films, which were deposited on Pt/SiO2/n-Si substrate by rf-magnetron sputtering and then annealed at 700degreesC for 60 min in air, were investigated. These SBVN films showed excellent ferroelectric properties in terms of a large remnant polarization (2P(r)) of similar to25 muC/cm(2) (2E(c)similar to200 kV/cm), fatigue free characteristics up to greater than or equal to10(8) switching cycles and a low current density of 10(-8) A/cm(2) at 100 kV/cm. X-ray diffraction and scanning electron microscope investigations indicate that the sputtered films exhibit a dense, well crystallized microstructure having random orientations and with a rather smooth surface morphology. The improved ferroelectric and leakage current characteristics obtained at the low processing temperature are attributed to the larger polarizability attained through increased rattling space in the distorted Nb(V)O-6 of the perovskite block due to the partial substitution of Nb with smaller V ions. The leakage current density of the SBVN thin films was studied at higher temperatures and the data were fitted with the Schottky and Poole-Frenkel emission models. (C) 2004 American Institute of Physics.