Banca de DEFESA: PEDRO HENRIQUE PESSOA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : PEDRO HENRIQUE PESSOA
DATE: 29/03/2024
TIME: 14:00
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:

MANUFACTURING OF Elongated NANOSTRUCTURES OF YTTRIUM IRON GARNETE (Y3Fe5O12) IN POROUS ALUMINA MEMBRANES THROUGH LOW-COST DEPOSITION METHODOLOGY

KEY WORDS:

Nanowires; magnetic oxides; yttrium iron garnet; YIG.

PAGES: 110
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

Yttrium iron garnet (Y 3 Fe 5 O 12 ), also known as YIG, has attracted a lot of attention due to its ease of magnetization, high electrical resistivity and low ferromagnetic resonance linewidth, thus making it an excellent material for the manufacture of magnetic-optical and microwave storage devices. In the literature, few studies have been carried out using YIG nanowires, so the proposal of this work is the deposition of YIG nanowires on porous alumina membranes using the sol-gel method, a relatively cheap and practical method, through a process of synthesis consisting of low-cost materials. Thus, elongated YIG nanostructures were produced using a sol composed of precursor metallic reagents, deposited on a porous alumina membrane and subjected to heat treatment in an electric oven at 900 ºC for 2h. YIG nanoparticles were also produced under the same conditions for comparative purposes. The results obtained through X-ray diffraction and Raman spectroscopy measurements confirmed the chemical composition of YIG and the presence of a secondary phase of yttrium iron oxide YFeO 3 , related to one of the garnet-forming precursor components. Elemental composition analyzes through energy dispersive spectroscopy (EDS) confirmed appropriate proportions of the constituent elements of the grenade. Using scanning electron microscopy images, it was possible to observe the formation of elongated nanostructures inside the pores, up to 5 µm in length. The samples were subjected to magnetic analysis by VSM, showing a ferromagnetic effect, with coercive and remanent fields of 21 Oe and 0.03 emu/g, respectively. Through ferromagnetic resonance measurements, it was possible to observe low anisotropy in the samples, as well as estimate the size of different groups of elongated nanostructures formed inside the pores, through adjustments made to Kittel's equation. Magnetic shielding tests in the X band allowed observing a low average effective shielding, suggesting future studies on shielding behavior at lower electromagnetic ranges.

COMMITTEE MEMBERS:
Externo à Instituição - MOHAMMAD REZA DOUSTI - UFRPE
Presidente - 2457389 - EDUARDO PADRON HERNANDEZ
Externo à Instituição - FREDERICO DUARTE DE MENEZES - IFPE
Interna - 2572606 - GLORIA MARIA VINHAS
Externo à Instituição - RAMÓN RAUDEL PEÑA GARCIA - UFRPE