Magnetophoretic Detection of Electron Spin Resonance in a Single Micro-Particle

我们研究了用磁电泳法检测微粒中的电子自旋共振(ESR)，这是一种在非均匀磁场下的迁移现象。用频率为0.1 GHz~20 GHz的微波辐射测量了分散在有机液体中的二氯化锰水溶液微滴的磁致伸缩速度。结果表明，只有在磁场满足ESR条件的位置，磁致伸缩速度才略有下降。因此，从磁化率的降低可以检测到微粒中的ESR。然而，速度下降的区域比预期的要宽。更详细地讨论微波功率的空间分布，以及更有效的辐照方法是用磁电法清晰观测ESR的关键。

We have examined to detect electron spin resonance (ESR) in a micro-particle by using magnetophoresis, which is migration phenomenon under an inhomogeneous magnetic field. Magnetophoretic velocity of micro-droplets of manganese dichloride aqueous solution dispersed in an organic liquid was measured with irradiation of microwave, whose frequency was from 0.1 GHz to 20 GHz. As a result, slight decrease of magnetophoretic velocity only at the position where the magnetic field met the condition of ESR was observed. Therefore, it was suggested that ESR in micro-particle could be detected from the decrease of the magnetic susceptibility. However, the region where the velocity decreased was broader than that expected. More detailed discussion about the spatial distribution of microwave power should be discussed, and more effective method for irradiation is essential for clear observation of ESR by magnetophoresis.