- 學位論文
四氧化三鐵奈米線於交變磁場下之運動行為
Motion Behavior of Fe3O4 Nanowires under an Alternating Magnetic Field
摘要
本研究使用熱氧化輔助氣固法製備四氧化三鐵奈米線，並利用非接觸式方式形成一交流電的交變磁場，藉以控制四氧化三鐵奈米線在液體中的運動行為。實驗時係將奈米線置於去離子水中，可降低凡德瓦力與表面張力等外力之影響，以利於交流電提供的交變磁場能有效的驅動奈米線旋轉。 實驗過程中探討兩根長度為8μ及12μ之奈米線，由1.0A至4.0A及60Hz至300Hz所提供的交流電所產生的交變磁場對於四氧化三鐵奈米線之轉動速度關係，並利用高速攝影機記錄其結果。結果顯示，長度8μm之四氧化三鐵奈米線可以在去離子水中被磁控並產生旋轉，當頻率在120Hz及電流在4.0A之條件下，其最高轉速可達到4171rpm，其移動速度達23.47μm/s，在相同條件下，8μ較12μ奈米線旋轉快速約1000rpm，移動速度快約3.91μm/s，此結果顯示以非接觸式的磁場方式控制四氧化三鐵奈米線在液體中的運動是可行的。
並列摘要
Oxide assisted vapor-solid (VS) process has been used for rapid synthesis of Fe3O4 nanowires (NWs) on a Si wafer. A noncontact manipulation mechanism for executing controllable motion behavior of Fe3O4 NWs in liquid by an alternating magnetic field has been developed. Experiments were executed to observe the relationships between the relative rotation speed and frequency of NWs under various currents from 1.0A to 4.0A. In addition, a CMOS high speed camera is connected to the control PC for recording of the microscope images. In experiments, a rotating magnetic field has been applied to actuate Fe3O4 NWs. The results show that NWs could be rotated in water by a rotating magnetic field. On the condition at a frequency of 120 Hz and a current of 4.0A, the max rotation speed of approximate is 4171 rpm for an 8 μm long NW. The results imply that magnetic field is promising approach for non-contact manipulation of Fe3O4 NWs in a controllable fashion.