Yamasaki Y, Sagayama H, Abe N, Arima T, Sasai K, Matsuura M, Hirota K, Okuyama D, Noda Y, Tokura Y
Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
Phys Rev Lett. 2008 Aug 29;101(9):097204. 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.
中子散射研究证明，正交钙钛矿RMnO₃（R = Gd₀.₇Tb₀.₃）中的铁电态显示出具有ab螺旋平面的摆线自旋态，以及沿a轴的自旋螺旋度相关极化矢量，它与更广泛观察到的具有bc螺旋平面的P||c态（例如，对于R = Tb和Dy）具有相同的微观起源（反Dzyaloshinskii-Moriya相互作用）。因此，RMnO₃中众所周知的磁场诱导极化从P||c翻转到P||a，被归因于自旋螺旋平面从bc到ab的正交翻转。
