體心立方結構鐵奈米粒子的製備與磁性分析

Synthesis of Monodisperse Iron Nanoparticles with Crystalline Body Centered Cubic Structure and Magnetic Analysis

黃瑞昌(Ruei-Chang Huang)

指導教授 ： 吉凱明

國立中正大學/理學院/化學暨生物化學系/碩士(2013年)

摘要

近年來，磁性奈米粒子因為顯現出塊材無法達到的有趣性質，使得它們被深入的研究。這些奈米尺寸的粒子可被應用於磁性儲存裝置、磁流體、磁阻系統，MRI顯影對比劑和藥物傳遞。目前有許多技術可以製備這些粒子，例如金屬蒸鍍法、化學法和雷射裂解法。而奈米粒子化學合成法是發展最快的領域，熱裂解法就是其中之一。
我們使用Fe(CO)5當作前驅物，在氮氣下的n-decane溶劑系統中進行熱裂解反應，嘗試加入不同界面活性劑，來製備單一分散且均一性的鐵奈米材料。經由實驗發現加入長碳鏈的氨類當作界面活性可以生成均一且分散性的奈米粒子，但是由XRD鑑定發現為非晶相的結構。當同時使用雙界面活性劑(oleyl amine 與 OTAB)，可得到粒徑約為14 nm球型鐵奈米粒子，而且經由XRD鑑定為BCC結構的鐵。
在鑑定方面，藉由穿透式電子顯微鏡(TEM)來觀察鐵奈米粒子的大小與形狀，並以電子繞射(ED)和X-ray粉末繞射儀(XRD)來鑑定奈米材料結構組成，藉由X-ray光電子能階譜來分析鐵奈米子的價數。另外，利用SQUID來量測奈米材料的磁性。

關鍵字

鐵奈米粒子 ； 磁性分析

並列摘要

Nanoscale magnetic materials are of interest for application in ferrofluid, high-density magnetic storge, high-frequency electronics, high-performance permanent magnets, magnetic refrigerants. Iron nanoparticles in the size range below 20 nm are in the superparamagnetic regime, and their stable dispersions with high magnetic moment are predicted to have important applications in bioseparation, biosensing, drug delivery, and MRI contrast enhancement.
We found that thermal decomposition of iron pentacarbonyl, Fe(CO)5, in n-decane in the presence of long carbon chain amines under a N2 atmosphere gave monodisperse Fe nanoparticles. X-ray diffraction (XRD) pattern of the as-synthesized Fe nanoparticles shows no obvious diffraction peaks, indicating that Fe nanoparticles are amorphous. Interestingly, when we use binary surfactant system (oleyl amine and OTAB) to prepare 14 nm spherical Fe nanoparticles, (110)、(200) and (220), X-ray diffraction peaks corresponding to the BCC-Fe are observed.
The characteriazation of the nanomaterials has been carried out by transmission electron microscope to analyze the morphology. The X-ray photoelectron spectroscopy and X-ray diffraction were used to confirm the composition of nanomaterials. Magnetic properties of the nanoparticles were also investigated by superconduting quantum interference device magnetometer.

並列關鍵字

Iron nanoparticles ； Magnetic Analysis

參考文獻

(3)Astruc, D. Nanoparticles and catalysis; Wiley-VCH, Weinheim, 2008

(4)Penn, S. G.; He, L.; Natan, M. J. Curr. Opin. Chem. Biol., 2003, 7, 609.

(7)Prinz, G. A. Science, 1998, 282, 1660.

(10) Buffet, Ph.; Borel, J.P. Phys. Rev. A, 1976, 13, 2287

(11) Kubo, R. J. Phys. Soc. Japan, 1962, 17, 975