Fabrication, Physical Properties and Microstructural Characterization of Nanostructured Ferroelectric Films

doi:10.3724/SP.J.1077.2010.00966

Abstract

Abstract:

By using pulsed laser deposition method, nanostructured BaTiO₃ ferroelectric films (with a thickness of 25 nm) were grown on Si substrates and coated by nanoporous alumina membranes (NAMs) with an average pore size of 25 nm. Metal Pt nanowires were embedded in NAMs as a part of the bottom electrode. The dielectric and ferroelectric properties, and microstructure of the nanostructured BaTiO₃ films were characterized. The results show that the dielectric constant of the BaTiO₃ nanofilms is decreased slowly from 196 to 190 as the increase of measured frequency from 10³ Hz to 10⁶ Hz, and their dielectric loss is increased slowly from 0.005 to 0.007 in the low frequency range from 10³ Hz to 10⁵ Hz, whereas quickly increased up to 0.013 at high frequencies over 10⁵ Hz. The remanent polarization and the coercive field of the BaTiO₃ nanofilms are 5 uC/cm² and 680 kV/cm, respectively. Cross-sectional (scanning) transmission electron microscope (TEM) images demonstrate that the BaTiO₃ nanofilms contact directly with the Pt nanowires, and the interface between them has some degree of waviness. Suitable post-annealing temperature is the critical processing parameter of fabricating nanostructured ferroelectric films as considering a trade-off between the ordered degree of metal nanowires within NAMs and the crystallinity of ferroelectric nanofilms.

Key words: BaTiO₃, nanostructured ferroelectric films, dielectric and ferroelectric properties, microstructure

CLC Number:

ZHU Xin-Hua, SONG Ye, HANG Qi-Ming, ZHU Jian-Min, ZHOU Shun-Hua, LIU Zhi-Guo. Fabrication, Physical Properties and Microstructural Characterization of Nanostructured Ferroelectric Films[J]. Journal of Inorganic Materials, 2010, 25(9): 966-970.

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