title: Raman scattering studies on multiferroic YMnO(3).
abstract: YMnO(3) is a multiferroic material in which ferroelectric and antiferromagnetic ordering can coexist. We have studied a YMnO(3) bulk crystal in detail by Raman scattering in a wide temperature range of 15-1200 K, with comparison to a previous experiment at room temperature and a theoretical prediction for Raman-active phonon modes. In the low-temperature ferroelectric phase, the observed phonon spectra showed anomalous temperature variation at the Néel temperature, T(N)∼80 K, suggesting a coupling between the spin and phonon systems below T(N). Furthermore, spectra for the high-temperature paraelectric phase, reported here for the first time, showed a sudden change at the Curie temperature T(C)>900 K, suggesting an abrupt structural phase change from the ferroelectric to the paraelectric phase.
authors.affiliation: Department of Electronics and Information Science, Kyoto Institute of Technology, Kyoto 606-8585, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Fukumura
authors.forename: S
authors.initials: S
authors.lastname: Matsui
authors.forename: H
authors.initials: H
authors.lastname: Harima
authors.forename: K
authors.initials: K
authors.lastname: Kisoda
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Yoshimura
authors.forename: N
authors.initials: N
authors.lastname: Fujimura