Banca de DEFESA: DIEGO BERNABE ORTIZ SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : DIEGO BERNABE ORTIZ SILVA
DATE: 15/04/2024
TIME: 09:00
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:

MANUFACTURING BY LITHOGRAPHY AND MICROMMAGNETIC SIMULATION OF PERMALLOY ELLIPSOID ARRANGEMENTS

KEY WORDS:

Microlithography. DWL. Magnetic arrangements. Permalloy. OOMMF.

PAGES: 82
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

The properties of object arrays have gained a lot of attention from the scientific community due to applications and still unsolved academic problems. An array can be studied magnetically using microscopy techniques. Numerical approximations can also be applied to obtain theoretical predictions with the solution of the micromagnetism equations. Especially when it comes to extensive arrays, whose objects present interactions, doubts arise as to the effects of the dipole energy of interaction between objects and the boundary conditions to be applied when solving the problem. When dealing with micrometric objects, different magnetization configurations can arise within the elements that form the array. In this work we present the fabrication of arrays of disks and ellipsoids arranged in square order. The responses obtained in magnetization measurements with different directions of the external field allow studying how each arrangement behaves. The measurements were carried out by applying an external magnetic field in the plane of the two-dimensional array and changing its orientation in relation to the main directions. The objects obtained here were manufactured with optical writing using the DWL66 system and Permalloy sputtering deposition. The deposition of magnetically soft material facilitates the fact of disregarding effects of magnetocrystalline anisotropy. Magnetic measurements were performed using vibrating sample magnetometry (MAV) which reveal soft ferromagnetic behavior at room temperature according to the simulations. The morphological characterization of the samples was performed by optical microscopy and scanning electron microscopy (SEM). For the micromagnetic simulations we use the Object Oriented Micromagnetism Framework (OOMMF) code to study the magnetization process of objects. The code is based on the Landau-Lifshitz-Gilbert equation to simulate the configuration of the magnetic moments and calculate the magnetization energy of the microstructures. The results are compared with data obtained experimentally. Coercive fields have an error of only 2%, possibly due to temperature conditions. The magnetization diagrams show the presence of multiple magnetization mechanisms in this system.

COMMITTEE MEMBERS:
Externo à Instituição - ALVARO ANTONIO OCHOA VILLA - IFPE
Presidente - 2457389 - EDUARDO PADRON HERNANDEZ
Externo à Instituição - JOSE ANGELO PEIXOTO DA COSTA - IFPE
Externo à Instituição - RAMÓN RAUDEL PEÑA GARCIA - UFRPE
Externo à Instituição - YUSET GUERRA DAVILA - UFPI