Department of Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, United Kingdom.
Phys Rev Lett. 2013 May 24;110(21):217206. doi: 10.1103/PhysRevLett.110.217206. Epub 2013 May 22.
Magnetic domains at the surface of a ferroelectric monodomain BiFeO(3) single crystal have been imaged by hard x-ray magnetic scattering. Magnetic domains up to several hundred microns in size have been observed, corresponding to cycloidal modulations of the magnetization along the wave vector k=(δ,δ,0) and symmetry equivalent directions. The rotation direction of the magnetization in all magnetic domains, determined by diffraction of circularly polarized light, was found to be unique and in agreement with predictions of a combined approach based on a spin-model complemented by relativistic density-functional simulations. Imaging of the surface shows that the largest adjacent domains display a 120° vortex structure.
硬 X 射线磁散射技术对铁电单畴 BiFeO(3)单晶表面的磁畴进行了成像。观察到尺寸可达数百微米的磁畴，对应于磁化强度沿波矢 k=(δ,δ,0)和对称等效方向的回旋调制。通过圆偏振光的衍射确定了所有磁畴中磁化的旋转方向，发现其是唯一的，并且与基于自旋模型与相对论密度泛函模拟相结合的综合方法的预测一致。对表面的成像表明，最大的相邻畴呈现出 120°的涡旋结构。
