Preparation of PMAA-coated Dysprosium Ferrite Ferrofluids and Study on the Superparamagnetism

作     者：ZHU Chuan-zheng SHEN Qin HU Xian-luo ZHANG Jie ZHAO Hong 

作者机构：Department of ChemistryEast China Normal UniversityShanghai 200062P.R.China 

出 版 物：《Chemical Research in Chinese Universities》 (高等学校化学研究(英文版))

年 卷 期：2002年第18卷第1期

页      面：30-33页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 

基　　金：Supported by the National Natural Science Foundation of China(No.2 97730 14) 

主　　题：Dy-ferrite ferrofluid Susceptibility Superparamagnetism Stability PMAA 

摘      要：The present paper covers the unprecedented preparation of stable aqueous Dy-ferrite ferrofluids, whereby colloidal Dy_ δ Fe_ 3- δ O_4 ultrafine particles were dispersed by using polymeric surfactant PMAA. The stabilities of the series of the ferrofluids were studied according to the stability indexes. The susceptibility measurements were made with a Farady-type magnetic balance at various temperatures and magnetic field intensities. In terms of Langevin function, the σ versus H/T curves showed that Dy-ferrite ferrofluids exhibited superparamagnetism behavior and the blocking temperatures were in the range from 160 to 200 K. Moreover, the ferrofluids were characterized by means of Infra-red spectroscopy, transmission electron microscopy, X-ray diffraction, and Mssbauer spectroscopy.