Magnetic inversion symmetry breaking and ferroelectricity in TbMnO3
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Date
2005-08-19
Journal Title
Journal ISSN
Volume Title
Publisher
American Physical Society
Abstract
TbMnO3 is an orthorhombic insulator where incommensurate spin order for temperature TN<41 K is accompanied by ferroelectric order for T<28 K. To understand this, we establish the magnetic structure above and below the ferroelectric transition using neutron diffraction. In the paraelectric phase, the spin structure is incommensurate and longitudinally modulated. In the ferroelectric phase, however, there is a transverse incommensurate spiral. We show that the spiral breaks spatial inversion symmetry and can account for magnetoelectricity in TbMnO3.
Description
Keywords
ferroelectric order, incommensurate spin order, orthorhombic insulator, spin structure, transverse incommensurate spiral, terbium compounds, neutron diffraction, ferroelectric transitions, antiferromagnetic materials, spatial inversion symmetry breaking, magnetoelectricity, TbMnO3
Citation
Physical Review Letters 19 Aug. 2005, vol.95, no.8, pp. 087206/1-4