Distinguishing different antiferromagnetic domains by electrical probes is a challenging task, which in itinerant compounds can be achieved, e.g., via the anisotropic magnetoresistance. Here, we demonstrate that in insulators, the anisotropic magnetocapacitance can be exploited for the same purpose. We studied the magnetic field dependence of the dielectric response in BiFeO3, one of the few room-temperature multiferroics. We observed a sizeable dielectric anisotropy upon the rotation of the modulation vector of the antiferromagnetic cycloid in the plane normal to the rhombohedral axis. Importantly, this anisotropy is characteristic of the cycloidal mono-domain state even in zero magnetic field, thus facilitating the determination of the antiferromagnetic domain population. This approach can be utilized to electrically distinguish between antiferromagnetic domains even in complex magnets, such as modulated spin structures, via the magnetodielectric coupling.

中文翻译：

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BiFeO3 中反铁磁摆线的各向异性磁电容


通过电探针区分不同的反铁磁畴是一项具有挑战性的任务，在流动化合物中，例如通过各向异性磁阻可以实现。在这里，我们证明了在绝缘体中，各向异性磁电容可以用于相同的目的。我们研究了 BiFeO3 中介电响应的磁场依赖性，BiFeO3 是为数不多的室温多铁金属之一。我们观察到，在垂直于菱面体轴的平面中，反铁磁摆线的调制矢量旋转时，存在相当大的介电各向异性。重要的是，即使在零磁场中，这种各向异性也是摆线单畴状态的特征，因此有助于确定反铁磁畴种群。这种方法可用于通过磁介电耦合在复杂磁体（例如调制自旋结构）中对反铁磁畴进行电气区分。