Banca de DEFESA: ACÁCIO SILVEIRA DE MELO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ACÁCIO SILVEIRA DE MELO
DATE: 04/06/2021
TIME: 09:00
LOCAL: Plataforma Google Meet
TITLE:

Anomalous Nernst Effect in magnetostrictive films on flexible substrate

KEY WORDS:

Magnetic anisotropy, magnetostrictive films, anomalous Nernst effect

PAGES: 102
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

The anomalous Nersnt effect (ANE) in nanostructured magnetic materials is a key phenomenon for optimizing control and using internal energy in electronic devices. In this work, we will explore the magnetic properties and ANE in a flexible magnetostrictive film with uniaxial anisotropy induced and subjected to mechanical stress, in addition, we will promote an integration between the ANE effect and the magnetostrictive phenomena, which in turn, in_uences the effective anisotropy of Films. Therefore, a theoretical study of the behavior of magnetization in this system will be presented, so that we can understand how it will influence the thermoelectric voltage response. At the same time, we will integrate this study with the experimental data obtained, in this way we can manipulate the ANE through the magnetic field and the applied mechanical stress. Theoretically, we calculate the magnetization behavior and the thermoelectric voltage response from the theoretical approach to planar geometry, with magnetic free energy density that takes into account the induced contributions of uniaxial and magnetoelastic anisotropy. Experimentally, we verified changes in the effective magnetic anisotropy, changing the applied stress, and explored the anomalous Nernst effect, as a powerful tool to investigate the magnetic properties of magnetostrictive materials. We found agreement between the experiment and the numerical calculations, thus elucidating the magnetic behavior and the thermoelectric voltage response. Finally, evidence was provided to confirm the validity of the theoretical approach to describe the magnetic properties and the anomalous Nernst effect in ferromagnetic magnetostrictive films with uniaxial magnetic anisotropy and subjected to external stresses.

BANKING MEMBERS:
Interno - 1345774 - CLAUDIONOR GOMES BEZERRA
Interno - 1508681 - FELIPE BOHN
Externo à Instituição - JOAO PAULO SINNECKER - CBPF
Externo à Instituição - JULIAN PENKOV GESHEV - UFRGS
Presidente - 1474380 - MARCIO ASSOLIN CORREA
Interno - 1788659 - MATHEUS GAMINO GOMES