title: Structural anomalies and multiferroic behavior in magnetically frustrated TbMn2O5.
abstract: We have studied the magnetostructural phase diagram of multiferroic TbMn2O5 as a function of temperature and magnetic field by neutron diffraction. Dielectric and magnetic anomalies are found to be associated with steps in the magnetic propagation vector, including a rare example of a commensurate-incommensurate transition on cooling below 24 K, and in the structural parameters. The geometrically frustrated magnetic structure is stabilized by "canted antiferroelectric" displacements of the Mn3+ ions, an example of the magnetic Jahn-Teller effect. The Tb moments order ferromagnetically at low temperatures in an applied field, while the Mn magnetic structure is largely unchanged.
authors.affiliation: ISIS Facility, Rutherford Appleton Laboratory-CCLRC, Chilton, Didcot, Oxfordshire, OX11 0QX, United Kingdom.
authors.forename: L C
authors.initials: LC
authors.lastname: Chapon
authors.forename: G R
authors.initials: GR
authors.lastname: Blake
authors.forename: M J
authors.initials: MJ
authors.lastname: Gutmann
authors.forename: S
authors.initials: S
authors.lastname: Park
authors.forename: N
authors.initials: N
authors.lastname: Hur
authors.forename: P G
authors.initials: PG
authors.lastname: Radaelli
authors.forename: S-W
authors.initials: SW
authors.lastname: Cheong