Perspective of Fe₃O₄ Nanoparticles Role in Biomedical Applications

Figure 9

The details of superparamagnetic behavior as a function of blocking temperature and relaxation time. In state (a), temperature is below the blocking temperature and the anisotropy energy is dominated to the thermal energy; so, the moments are apparently fixed. In state (b), temperature is higher than blocking point and the thermal energy is larger than anisotropy one; thereby, the superparamagnetic structure is formed [95].

(a)

(b)