Photothermal Effect of Superparamagnetic Fe₃O₄ Nanoparticles Irradiated by Near-Infrared Laser

Figure 5

(a) Photothermal effect of the irradiation of Fe₃O₄ NP suspensions with an 808 nm laser. The suspension is irradiated for 15 min and cooled to room temperature under ambient environment. (b–d) Plot of cooling time versus negative natural logarithm of the temperature driving force obtained from the cooling stage.

(a)

(b)

(c)

(d)