Abstract
Lattice modulation and magnetic structures in magnetoelectric compounds Tb1-xDyxMnO3 have been studied around the ferroelectric (FE) Curie temperature TC by x-ray and neutron diffraction. Temperature-independent modulation vectors through TC are observed for the compounds with 0.50≤x≤0.68. This indicates that ferroelectricity with a polarization (P) along the c axis in the RMnO3 series cannot be ascribed to such an incommensurate-commensurate transition of an antiferromagnetic order as was previously anticipated. A neutron diffraction study with x=0.59 shows that the FE transition is accompanied by the transformation of the Mn-spin alignment from sinusoidal (collinear) antiferromagnetism into a transverse-spiral structure. The observed spiral structure below TC is expected to produce P along the c axis with the "inverse" Dzialoshinski-Moriya interaction, which is consistent with observation.
Original language | English |
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Article number | 097202 |
Journal | Physical review letters |
Volume | 96 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2006 |
ASJC Scopus subject areas
- Physics and Astronomy(all)