masterThesis
Comportamento térmico em regime não-adiabático de nanopartículas superparamagnéticas sob ação de um campo magnético oscilante
Fecha
2018-03-09Registro en:
IGLESIAS, Carlos Augusto de Moraes. Comportamento térmico em regime não-adiabático de nanopartículas superparamagnéticas sob ação de um campo magnético oscilante. 2018. 86f. Dissertação (Mestrado em Física) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2018.
Autor
Iglesias, Carlos Augusto de Moraes
Resumen
The phenomena of raising the temperature of magnetic nanoparticles under an alternating
magnetic field, known as magnetic hyperthermia, is an outstanding field, which
gives rise to challenges in the context of fundamental physics and providing new roads
to applications, such as in the cancer treatment and in the control of thermally activated
drug delivery. Thus, the complete understanding of the behavior of these systems with
reduced dimensions becomes a key point and the optimization of the production processes
and the properties of these materials, a challenging task. In this work, we perform a theoretical
and experimental investigation of the magnetic hyperthermia in MgO:F e2O3 and
FeO:F e2O3 superparamagnetic nanoparticles. Specifically, we aim to fully understand
the influence of the composition, nanoparticle size, as well as amplitude and frequency of
the field on the specific absorption rate of the samples. Here, we propose a theoretical model
to describe the thermal behavior of magnetic nanoparticles, providing further insights
on well-known parameters found in literature. To test the robustness of the approach,
we apply the theoretical model to describe the magnetic hyperthermia curves obtained
experimentally. To obtain the magnetic hyperthermia curves, an experimental system is
developed, making possible to generate magnetic fields with frequency up to 100 kHz and
amplitude up to 200 Oe. The excellent agreement between theoretical and experimental
results provides support to confirm the validity of our approach to describe the thermal
behavior of magnetic nanoparticles.