Banca de QUALIFICAÇÃO: PEDRO HENRIQUE PESSOA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : PEDRO HENRIQUE PESSOA
DATE: 13/06/2022
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:

Fabrication of magnetic oxide nanowires in porous alumina membranes

KEY WORDS:

Nanowires; magnetic oxides; itrium-iron garnet; YIG; magnetic properties.

PAGES: 50
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

With the advance of technology, the effects of the magnetic properties existing within nanoscale materials has been frequently studied. Among the materials used, the Yttrium iron garnet (Y3Fe5O12), also known as YIG, has attracted a lot of attention due to its ease of magnetization, high electrical resistivity and narrow ferromagnetic resonance line width, thus making it an excellent material for the development of magnetic-optical storage devices and microwave devices. In the literature, few studies have been carried out using one-dimensional YIG nanoestructures, so we have as a proposal of this work the deposition of nanowires/nanotubes of pure YIG in porous anodic alumina membranes using the sol-gel method, a relatively inexpensive and practical one in relation to other production techniques. YIG solution was prepared by dissolving a 3:5 stoichiometric ratio of the precursor reagents, using three solvent systems: ethylene glycol monobutyl ether, deionized water and a 50/50% vol of both previous solvents. The solutions were then placed in eppendorfs and membrane samples were completely immersed in the solution during 1 hour. During this period, vacuum was applied to the system. Subsequently, the samples underwent heat treatment at 900 ºC during 2 hour to form the YIG phase in the template. XRD analysis was performed and a single rhombohedral YIG phase was found, with a crystallite size of 29,6 nm for the most intense peak at 2θ = 30,36. To investigate the deposition of the material inside the nanopores, a SEM test was performed, where a greater deposition was observed for samples prepared with deionized water as solvent, indicating greater permeability for this system. As perspectives, optimize the heat treatment process and preparation for the formation of uniform and good quality nanowires, as well as the evaluation of it’s magnetic properties. Further study including doping the YIG solution with zinc to obtain doped YIG nanowires will also be carried out, where a comparative study of its magnetic properties such as ferromagnetic linewidth and saturation magnetization will be made.

BANKING MEMBERS:
Presidente - 2572606 - GLORIA MARIA VINHAS
Externo à Instituição - JOAO MARIA SOARES - UFRN
Externa ao Programa - 3218211 - MARCELLA AUXILIADORA DE MELO LUCENA