Role of dipolar interaction in magnetic hyperthermia

Colloidal magnetic nanocrystal clusters: variable length-scale interaction mechanisms, synergetic functionalities and technological advantages

“…The former group of authors followed an approach based on the Landau-Lifschitz-Gilbert equation of motion; having included Langevin dynamics for the thermal response, a decreased hysteresis area and a reduced heating effect have been found for the systems of high concentration [152]. The second team of authors, having included dipolar interactions in the Fokker-Planck equation, which describes the time evolution of the system, indicated that even moderate changes in the particle concentration may have significant effect on the heat dissipation [153]. The thermal response first increases up to a point where the dipolar interactions become comparable with the anisotropy field, after which it starts to decrease with the concentration in this second model [153].…”

“…In addition to the SLP enhancement because of dipolar interaction effects, the exact way in which this type of mechanism affects the dynamics of a system, and as a result, the heat dissipation in hyperthermia experiments has been the aim of models developed by Haase et al [152] and Landi et al [153]. The former group of authors followed an approach based on the Landau-Lifschitz-Gilbert equation of motion; having included Langevin dynamics for the thermal response, a decreased hysteresis area and a reduced heating effect have been found for the systems of high concentration [152].…”

A microscopic model of ballistic-diffusive crossover

“…(8), (10) energy transmission in carbon nanotubes [32,31], current in Heisenberg model [21] has been introduced recently; a more generic scaling form, Eq. (9), has also been obtained for conductivity in anharmonic chains [29].…”

“…This ballistic-diffusive crossover has also been observed experimentally in many low-dimensional systems such as the graphene nanoribbon [6], SiGe nanowires [7], stretched polymer nanofibres [24], carbon nanotubes [25] and other nanowires [26]. Several theoretical attempts have been made [27] to understand this ballistic-diffusive crossover in the coarse grained level, dealing with Boltzmann transport equations [28], scaling theory [21,29], Langevin dynamics [30], the Buttiker formalism [31] or the nonequilibrium Greens function approach [32] etc. However, a unified microscopic formalism that goes beyond the recent phenomenological attempts [28,29,30,31,32,33,34,35] and consistently describes both the regimes is still lacking.…”

“…Several theoretical attempts have been made [27] to understand this ballistic-diffusive crossover in the coarse grained level, dealing with Boltzmann transport equations [28], scaling theory [21,29], Langevin dynamics [30], the Buttiker formalism [31] or the nonequilibrium Greens function approach [32] etc. However, a unified microscopic formalism that goes beyond the recent phenomenological attempts [28,29,30,31,32,33,34,35] and consistently describes both the regimes is still lacking. Here we propose a scaling ansatz for the heat current in driven finite systems in terms of the size and the characteristic length scale of the system.…”