title: Ferroelectricity in ultrathin BaTiO3 films: probing the size effect by ultraviolet Raman spectroscopy.
abstract: We demonstrate the dramatic effect of film thickness on the ferroelectric phase transition temperature Tc in strained BaTiO3 films grown on SrTiO3 substrates. Using variable-temperature ultraviolet Raman spectroscopy enables measuring Tc in films as thin as 1.6 nm, and a film thickness variation from 1.6 to 10 nm leads to Tc tuning from 70 to about 925 K. Raman data are consistent with synchrotron x-ray scattering results, which indicate the presence of 180 degrees domains below Tc, and thermodynamic phase-field model calculations of Tc as a function of thickness.
authors.affiliation: Department of Physics, Boise State University, 1910 University Drive, Boise, Idaho 83725-1570, USA. dmitritenne@boisestate.edu
authors.forename: D A
authors.initials: DA
authors.lastname: Tenne
authors.forename: P
authors.initials: P
authors.lastname: Turner
authors.forename: J D
authors.initials: JD
authors.lastname: Schmidt
authors.forename: M
authors.initials: M
authors.lastname: Biegalski
authors.forename: Y L
authors.initials: YL
authors.lastname: Li
authors.forename: L Q
authors.initials: LQ
authors.lastname: Chen
authors.forename: A
authors.initials: A
authors.lastname: Soukiassian
authors.forename: S
authors.initials: S
authors.lastname: Trolier-McKinstry
authors.forename: D G
authors.initials: DG
authors.lastname: Schlom
authors.forename: X X
authors.initials: XX
authors.lastname: Xi
authors.forename: D D
authors.initials: DD
authors.lastname: Fong
authors.forename: P H
authors.initials: PH
authors.lastname: Fuoss
authors.forename: J A
authors.initials: JA
authors.lastname: Eastman
authors.forename: G B
authors.initials: GB
authors.lastname: Stephenson
authors.forename: C
authors.initials: C
authors.lastname: Thompson
authors.forename: S K
authors.initials: SK
authors.lastname: Streiffer