Figure 5.

RT magnetization curves for the of CoFe2O4 MSs with different reaction time: a 12 h, b 24 h (The inset shows enlarged magnetic hysteresis loops at low applied fields); photographs of CoFe2O4 MSs dispersion in a vial, c without magnetic field, d with magnetic field for 1 min

Yuan et al. Nanoscale Research Letters 2010 5:1817-1821   doi:10.1007/s11671-010-9718-7