Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10714191 | Physica B: Condensed Matter | 2012 | 4 Pages |
Abstract
Effects of film thickness on the piezoelectric property of the ultrathin BiFeO3 films (t=1-150Â nm), grown on the (0Â 0Â 1)-SrTiO3 substrates with a La0.67Sr0.33MnO3 cover layer, have been studied by the technique of piezoresponse force microscope. Special attention has been paid to the evolution of the piezoelectric response with film thickness. Well ferroelectric property maintains in the BFO film with a thickness down to 6Â nm, below which no obvious ferroelectric domains are observed. Based on careful analysis of the piezoelectric response images of the ferroelectric domains upwards or downwards poled by external field, a quantitative description of the piezoelectric coefficient d33 can be obtained. d33 is found to display a monotonic decrease with the decrease of film thickness, descending from â¼46Â pm/V for t=150Â nm to â¼8Â pm/V for t=6Â nm. A corresponding growth of the out-of-plane lattice parameter of the film from 4.011Â Ã
to 4.077Â Ã
is also observed. The effects of depolarization, lattice strains and substrate clamping on the piezoelectric property of the films are discussed.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
J.L. Zhao, H.X. Lu, J.R. Sun, B.G. Shen,