Diamagnetic levitation and thermal gradient driven motion of graphite
Diamagnetic levitation and thermal gradient driven motion of graphite
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DOI：
10.1103/physrevb.100.045405
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发表时间：
2019-04
影响因子：
3.7
通讯作者：
Manato Fujimoto;M. Koshino
中科院分区：
文献类型：
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作者：
Manato Fujimoto;M. Koshino
我们从理论上研究了石墨的反磁悬浮和热驱动运动。利用量子力学推导的磁化率，我们计算了磁体周期性排列上悬浮石墨的平衡位置，并研究了悬浮高度对磁化率和几何形状的依赖性。我们发现，悬浮高度在磁体的某个周期处达到最大，并且最大高度与悬浮物体的磁化率成线性比例。我们比较了普通AB堆叠石墨和随机堆叠石墨，结果表明后者表现出很大的悬浮长度，特别是在低温下，因为它的抗磁性与温度成反比。最后，我们证明温度梯度将悬浮物体移向高温侧，并估计产生的力作为磁化率的函数。
We theoretically study the diamagnetic levitation and the thermal-driven motion of graphite. Using the quantum-mechanically derived magnetic susceptibility, we compute the equilibrium position of levitating graphite over a periodic arrangement of magnets, and investigate the dependence of the levitation height on the susceptibility and the geometry. We find that the levitation height is maximized at a certain period of the magnets, and the maximum height is then linearly proportional to the susceptibility of the levitating object. We compare the ordinary AB-stacked graphite and a randomly stacked graphite, and show that the latter exhibits a large levitation length particularly in low temperatures, because of its diamagnetism inversely proportional to the temperature. Finally, we demonstrate that the temperature gradient moves the levitating object towards the high temperature side, and estimate the generated force as a function of susceptibility.