Ferroelectricity at the Nanoscale: Local Polarization in Oxide Thin Films and Heterostructures
C. H. Ahn,1*
K. M. Rabe,2*
J.-M. Triscone3*
Ferroelectric oxide materials have offered a tantalizing potential for applications since the discovery of ferroelectric perovskites more than 50 years ago. Their switchable electric polarization is ideal for use in devices for memory storage and integrated microelectronics, but progress has long been hampered by difficulties in materials processing. Recent breakthroughs in the synthesis of complex oxides have brought the field to an entirely new level, in which complex artificial oxide structures can be realized with an atomic-level precision comparable to that well known for semiconductor heterostructures. Not only can the necessary high-quality ferroelectric films now be grown for new device capabilities, but ferroelectrics can be combined with other functional oxides, such as high-temperature superconductors and magnetic oxides, to create multifunctional materials and devices. Moreover, the shrinking of the relevant lengths to the nanoscale produces new physical phenomena. Real-space characterization and manipulation of the structure and properties at atomic scales involves new kinds of local probes and a key role for first-principles theory.
1 Departments of Applied Physics and Physics, Yale University, Post Office Box 208284, New Haven, CT 06520–8284, USA.
2 Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854–8019, USA.
3 Condensed Matter Physics Department, University of Geneva, 24quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland.
* To whom correspondence should be addressed. E-mail: charles.ahn{at}yale.edu (C.H.A.), rabe{at}physics.rutgers.edu (K.M.R.), jean-marc.triscone{at}physics.unige.ch (J.-M.T.)
