Banca de DEFESA: CASSIANO MINORU AONO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : CASSIANO MINORU AONO
DATA : 16/02/2022
HORA: 14:00
LOCAL: https://conferenciaweb.rnp.br/webconf/fabio-27
TÍTULO:

Magnetic dynamics of aggregates of magnetic nanoparticles and its influences in the efficiency of magneto-hyperthermia

PÁGINAS: 73
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
SUBÁREA: Física Atômica e Molecular
ESPECIALIDADE: Estrutura Eletrônica de Átomos e Moléculas; Teoria
RESUMO:

The focus in this work was to study how some physical factors influence the efficiency of magneto-hyperthermia. Thereunto, a series of routines were developed, this routines run an algorithm based on kinetic Monte-Carlo and that uses the Stoner-Wohlfarth model as a basis. This algorithm was validated through comparisons between theoretical and experimental results besides comparisons with other algorithms already validated in the literature. The created routines proved to be a powerful computational tool useful for carrying out systematic studies of magnetic fluids under different conditions. Through the use of this algorithm was possible to study the influences of the characteristics of the external magnetic field, concentration of magnetic fluids, the different forms of aggregates, among other factors. From the point of view of computational cost, the algorithm based on the Stoner-Wohlfarth model combined with the kinetic Monte-Carlo method proved to be more efficiency than algorithms that integrate the Landau-LifshitzGilbert equation directly, but both observe the same trends and the software developed in this work allows simulating systems closer to those studied experimentally, which makes it a better tool for the desired studies in this work. Besides to the legacy of a robust and low computational cost algorithm, using these routines it was possible to understand some fundamental aspects of the heat release process, such as the fact that the formation of aggregates can contribute to the increase in the energy released due to creation of constraints between the easy magnetization axes of nanoparticles. The simulations showed that the linear chains parallel to the external field are the aggregates shape that most contributes to the energy release process. Finally, it was possible to demonstrate that there must be an optimal size of linear chains, a fact already observed experimentally by collaborators and which was proven by simulations as well.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1734908 - FABIO FURLAN FERREIRA
Membro Titular - Examinador(a) Externo à Instituição - JAMES MORAES DE ALMEIDA - CNPEM
Membro Titular - Examinador(a) Externo à Instituição - MICHELE APARECIDA SALVADOR - USP
Membro Titular - Examinador(a) Externo à Instituição - GABRIEL TEIXEIRA LANDI - USP
Membro Suplente - Examinador(a) Interno ao Programa - 1671599 - MARCOS DE ABREU AVILA
Membro Suplente - Examinador(a) Externo à Instituição - LEONARDO LUIZ E CASTRO - UNB