Low-Temperature Preparation of Superparamagnetic CoFe(2)O(4) Microspheres with High Saturation Magnetization.
Based on a low-temperature route, monodispersed CoFe(2)O(4) microspheres (MSs) were fabricated through aggregation of primary nanoparticles. The microstructural and magnetic characteristics of the as-prepared MSs were characterized by X-ray diffraction/photoelectron spectroscopy, scanning/transmitting electron microscopy, and vibrating sample magnetometer. The results indicate that the diameters of CoFe(2)O(4) MSs with narrow size distribution can be tuned from over 200 to ~330 nm. Magnetic measurements reveal these MSs exhibit superparamagnetic behavior at room temperature with high saturation magnetization. Furthermore, the mechanism of formation of the monodispersed CoFe(2)O(4) MSs was discussed on the basis of time-dependent experiments, in which hydrophilic PVP plays a crucial role.
Key Lab for Special Functional Materials of Ministry of Education, Henan University, 475004 Kaifeng, People's Republic of China.
Hong Lei
HL
Yuan
Yong Qiang
YQ
Wang
Shao Min
SM
Zhou
Li Sheng
LS
Liu
Xi Liang
XL
Chen
Shi Yun
SY
Lou
Rui Jian
RJ
Yuan
Yao Ming
YM
Hao
Ning
N
Li