Nanoscale polarization profile across a 180 degrees ferroelectric domain wall extracted by quantitative piezoelectric force microscopy

作者:Tian Lili*; Vasudevarao Aravind; Morozovska Anna N; Eliseev Eugene A; Kalinin Sergei V; Gopalan Venkatraman
来源:Journal of Applied Physics, 2008, 104(7): 074110.
DOI:10.1063/1.2979973

摘要

The structure of a single antiparallel ferroelectric domain wall in LiNbO(3) is quantitatively mapped by piezoelectric force microscopy (PFM) with calibrated probe geometry. The PFM measurements are performed for 49 probes with the radius varying from 10 to 300 nm. The magnitude and variation of the experimental piezoelectric coefficient across a domain wall match the profiles calculated from a comprehensive analytical theory, as well as three-dimensional finite element method simulations. Quantitative agreement between experimental and theoretical profile widths is obtained only when a finite disk-type tip radius that is in true contact with the sample surface is considered, which is in agreement with scanning electron microscopy images of the actual tips after imaging. The magnitude of the piezoelectric coefficient is shown to be independent of the tip radius, and the PFM profile width is linearly proportional to the tip radius. Finally we demonstrate a method to extract any intrinsic material broadening of the ferroelectric wall width. Surprisingly wide wall widths of up to 100 nm are observed in the limit of zero tip radius.

  • 出版日期2008-10-1