Abstract
Artificial superlattices were constructed using off-axis rf magnetron sputtering. X-ray diffraction and piezoelectric atomic force microscopy were used to study the evolution of the ferroelectric polarization as the ratio of to was changed. For layer thicknesses larger than the 3-unit cell thickness used in the structure, the polarization is found to be reduced as the thickness is decreased. This observation confirms the primary role of the depolarization field in the polarization reduction in thin films. For the samples with ratios of to of less than one, a surprising recovery of ferroelectricity that cannot be explained by electrostatic considerations was observed.
- Received 17 June 2005
DOI:https://doi.org/10.1103/PhysRevLett.95.177601
©2005 American Physical Society