Cycloidal spin order in the a-axis polarized ferroelectric phase of orthorhombic perovskite manganite.
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.
Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
Y
Y
Yamasaki
H
H
Sagayama
N
N
Abe
T
T
Arima
K
K
Sasai
M
M
Matsuura
K
K
Hirota
D
D
Okuyama
Y
Y
Noda
Y
Y
Tokura