DC 欄位 |
值 |
語言 |
DC.contributor | 物理學系 | zh_TW |
DC.creator | 傅喬玟 | zh_TW |
DC.creator | Chiau-Wen Fu | en_US |
dc.date.accessioned | 2007-7-16T07:39:07Z | |
dc.date.available | 2007-7-16T07:39:07Z | |
dc.date.issued | 2007 | |
dc.identifier.uri | http://ir.lib.ncu.edu.tw:88/thesis/view_etd.asp?URN=942202020 | |
dc.contributor.department | 物理學系 | zh_TW |
DC.description | 國立中央大學 | zh_TW |
DC.description | National Central University | en_US |
dc.description.abstract | 本實驗採用熱蒸鍍法製備數組Cu 奈米微粒,經過氧化後形成
Cu/Cu2O 奈米微粒,最後採用三組樣品粒徑分別為3.4 nm、2.3 nm 與3.9 nm。並使用物理特性量測系統(Physical property measurement system)量測其磁性,利用朗之萬函數(Langevin function)加上一線性項擬合實驗,此線性項為順磁與反磁一起貢獻的結果,進而分析其磁性。
在塊材的銅與氧化亞銅皆為反磁性,但此實驗發現在低磁場部分
由鐵磁性表現,高磁場則為銅與氧化亞銅共同表現的現象,當溫度升高時反磁現象越明顯,不過當Cu2O 變多時反而是使反磁性降低。由此也可推測出核內的銅在奈米尺度下能為反磁性,但氧化亞銅則與塊材實的磁性有所不同。在磁矩與溫度的關係上,則發現磁矩排列隨溫度上升而變大的特性,μP ~ kBT。而造成這些與塊材磁性相異的原因,推測乃因表面電子自旋極化與Cu/Cu2O 部分氧缺陷所造成。 | zh_TW |
dc.description.abstract | Copper nanoparticles were fabricated by the thermal evaporation method. A series of copper nanoparticles were oxided to form core-shell structure. The diameters of 3.4 nm, 2.3 nm and 3.9 nm Cu/Cu2O nanoparticles were determined by atomic force microscope images.
We observe the spin polarization in Cu/Cu2O fine particles. The applied magnetic field dependency of magnetization (M-H curve) can be described by using Langevin function. And we also find two magnetic
components in Cu/Cu2O nanoparticles at low temperatures. We can find that the fitting parameters μp increase with increasing temperature. According to ferromagnetic component in M-H curves and remanence, the ferromagnetic spin polarization of Cu/Cu2O nanoparticles is observed. | en_US |
DC.subject | 自旋極化 | zh_TW |
DC.subject | spin polarization | en_US |
DC.title | 核殼結構的奈米Cu/Cu2O微粒之自旋極化與弱鐵磁現象 | zh_TW |
dc.language.iso | zh-TW | zh-TW |
DC.title | The spin polarization and weak ferromagnetism in core-shell Cu/Cu2O nanoparticles. | en_US |
DC.type | 博碩士論文 | zh_TW |
DC.type | thesis | en_US |
DC.publisher | National Central University | en_US |