Cycloidal spin order in the a-axis polarized ferroelectric phase of orthorhombic perovskite manganite

• Published in: Physical review letters Vol. 101; no. 9; p. 097204
• Main Authors: Yamasaki, Y, Sagayama, H, Abe, N, Arima, T, Sasai, K, Matsuura, M, Hirota, K, Okuyama, D, Noda, Y, Tokura, Y
• Format: Journal Article
• Language: English
• Published: United States 29-08-2008
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.101.097204

The ferroelectric state in an orthorhombic perovskite RMnO3 (R=Gd0.7Tb0.3) was proved by neutron scattering studies to show the cycloidal spin state with the ab-spiral plane and the spin-helicity dependent polarization vector along the a axis, sharing the microscopic origin (inverse Dzyaloshinskii-Moriya interaction) with the more widely observed P||c state (e.g., for R=Tb and Dy) with the bc-spiral plane. The magnetic-field induced polarization flop from P||c to P||a as well known for RMnO3 is thus assigned to the orthogonal flop of the spin spiral plane from bc to ab.