奈米氧化亞銅微粒的氧化缺陷及自旋極化; The oxygen vacancy and spin polarization of cuprous oxide nanoparticle

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/7503

Title:	奈米氧化亞銅微粒的氧化缺陷及自旋極化;The oxygen vacancy and spin polarization of cuprous oxide nanoparticle
Authors:	林裕翔;Yu-shiang Lin
Contributors:	物理研究所
Keywords:	自旋極化;奈米微粒;氧化亞銅;cuprous oxide;nanoparticle;spin polarization
Date:	2007-06-20
Issue Date:	2009-09-22 10:59:00 (UTC+8)
Publisher:	國立中央大學圖書館
Abstract:	為了探討奈米氧化亞銅微粒磁特性，我們對奈米氧化亞銅微粒進行ㄧ系列M-H 量測，在低溫1.8 K 及5 K 發現有磁滯現象。對樣品壓合以調控其微粒間距，探討微粒間距對其磁性的影響，其聚合密度(CD值)範圍為3%至77%。在奈米氧化亞銅微粒系統中，發現其M-H 曲線由兩種磁性來源而成，可用兩個朗之萬函數去擬合實驗M-H 曲線。推測一種來源為表面自旋極化現象，在低場較為明顯；另一種為Cu2O0.9 奈米微粒磁特性，所引起的鐵磁行為。低場自旋極化的飽和磁化強度Ms，隨著微粒間距縮小而增大，呈現類似磁偶極間交互作用的現象，飽和磁化強度Ms 與微粒間距三次方成反比關係。而壓合後低溫M-H 曲線未再出現磁滯現象，且開始顯現反磁性質，高溫M-H 曲線呈現轉為負值斜率的線性變化，Cu2O0.9 奈米微粒磁特性有減弱的趨勢。 In studying the magnetic properties of cuprous oxide nanoparticle. We got a group of M-H curve measurements of cuprous oxide nanoparticle and discovered hysteresis at 1.8 K and 5 K. Then we pressed the cuprous oxide sample to control the interparticle separation, and dicussed the effect of interparticle interaction. The range of compacting density (CD) of particles is from 3 % to 77 % . There are two magnetic components in cuprous oxide nanoparticle system. We infer that one component is surface spin polarization and the other is magnetic characters of Cu2O0.9nanoparticle. The saturated magnetization (Ms) of spin polarization increases as the interparticle separation is decreased. The behavior can be taken the form of magnetic dipole-dipole interaction. After pressing the sample,we never discovered hysteresis again and diamagnetic properties was revealed.
Appears in Collections:	[Graduate Institute of Physics] Electronic Thesis & Dissertation

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