Below its N\'eel temperature, the frustrated magnet CdCr$_2$O$_4$ exhibits an antiferromagnetic spin-spiral ground state. Such states can give rise to a sizable magnetoelectric coupling. In this report, we measure the electric polarization induced in single-crystalline CdCr$_2$O$_4$ by a large applied magnetic field. Because the detection of a macroscopic polarization is hindered by the structural domains in the tetragonal spin-spiral phase, we have pioneered an alternative method of measuring polarization induced by high magnetic fields, using electrostatic force microscopy. This method enables us to measure polarization from nanometer sized areas of the sample surface, as well as imaging how to charge inhomogeneities change with magnetic field.

中文翻译：

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使用高场扫描探针显微镜研究受挫尖晶石中的磁电耦合

低于其 N\'eel 温度，受挫磁铁 CdCr$_2$O$_4$ 表现出反铁磁自旋螺旋基态。这种状态会产生相当大的磁电耦合。在本报告中，我们测量了大外加磁场在单晶 CdCr$_2$O$_4$ 中引起的电极化。由于四方自旋螺旋相中的结构域阻碍了宏观极化的检测，因此我们开创了一种使用静电力显微镜测量由高磁场引起的极化的替代方法。这种方法使我们能够测量样品表面纳米尺寸区域的极化，以及成像如何随磁场变化电荷不均匀性。