DOI: 10.1126/science.1098252 ISSN:
Ferroelectricity in Ultrathin Perovskite Films
Dillon D. Fong, G. Brian Stephenson, Stephen K. Streiffer, Jeffrey A. Eastman, Orlando Auciello, Paul H. Fuoss, Carol Thompson- Multidisciplinary
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.