Magnetic Nanoparticles: A Subject for Both Fundamental Research and Applications

Figure 10

(a) Real and imaginary components, 𝜒^′(𝑇) and 𝜒^′′(𝑇), of the 𝑎𝑐 susceptibility measured on [Co₈₀Fe₂₀(𝑡_𝑛=0.9 nm)/Al₂O₃(3 nm)]₁₀ at frequencies 10⁻²≤𝑓≤10² Hz. (b) Arrhenius law fit (straight line) to log₁₀[𝜏/𝑠] versus 1/𝑇_𝑚, where 𝑇_𝑚 corresponds to the peak position of 𝜒^′(𝑇). (c) Double logarithmic plot of 𝜏 versus 𝑇_𝑚/𝑇_𝑔−1 and best fit to a power law (straight line). Reproduced with permission from Sahoo et al. [91] © 2003, AIP Publishing LLC.