Strongly interacting superspins in Fe3O4 nanoparticles

Solvothermal synthesis of MnFe2O4 nanoparticles: The role of polymer coating on morphology and magnetic properties

“…Despite the analysis of temperature dependence of frequency is quite critical with such a broad maximum, tentative scaling has been performed for T10 -T30 samples (T0 and T5 were excluded because it was impossible to identify a clear maximum for these samples). In no cases the frequency dependence of T P can be described by an Arrhenius law, leading to unphysical values of the characteristic relaxation time (τ 0 ) and the energy barrier (E a ) [22,23]. This is in agreement with the presence of interparticle interactions, which influence the magnetization dynamics of superspins.…”

Memory effect in weakly-interacting Fe3O4 nanoparticles

“…However, there have also been reports where FM and AFM materials exhibit spin-glass like behavior due to strong interparticle interaction between the nanoparticles of ferrites18,13 . They found that the magnetization dynamics can be described by the Néel-Brown 17 model of non-interacting, unidirectional anisotropy energy.…”

Structural and Magnetic Properties of Microwave Assisted Sol-Gel Synthesized La0.9Sr0.1MnO3Eshraghi1, Kameli2 2014ISRN Nanotechnology2010View full textAdd to dashboardCite

“…Figure 4 shows the real, ( ), and imaginary, ( ), parts of ac magnetic susceptibility as function of temperature in an ac field of 10 Oe and frequencies of 33, 111, 333, 666, and 1000 Hz. It is evident that by decreasing the temperature, the ( ) and ( ) show a peak related to the blocking/freezing temperature ( ) of the SPM/spin glass systems [20][21][22]. Above , the nanoparticles considered being in the SPM regime and below which the nanoparticles are in the socalled blocked/freezed regime.…”