323145.fig.004a
(a)
323145.fig.004b
(b)
Figure 4: Temperature dependent magnetization curves measured at an applied field of 200 Oe (a) at low temperatures between 20 and 300 K under ZFC and FC conditions and (b) at high temperatures for as-prepared CoFe2O4–Fe2O3 magnetic nanoparticles. Inset: Plot of thermal derivative of magnetization with temperature.