Ferroelectricity in ultrathin perovskite films.
Understanding the suppression of ferroelectricity in perovskite thin films is a fundamental issue that has remained unresolved for decades. We report a synchrotron x-ray study of lead titanate as a function of temperature and film thickness for films as thin as a single unit cell. At room temperature, the ferroelectric phase is stable for thicknesses down to 3 unit cells (1.2 nanometers). Our results imply that no thickness limit is imposed on practical devices by an intrinsic ferroelectric size effect.
Fong
Dillon D
DD
Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA.
Stephenson
G Brian
GB
Streiffer
Stephen K
SK
Eastman
Jeffrey A
JA
Auciello
Orlando
O
Fuoss
Paul H
PH
Thompson
Carol
C