The Rietveld Method: a tool for the structural refinement of magnetic oxide compounds

• Grant number: 19/08486-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2019
• End date: August 31, 2020
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Dario de Almeida Jané
• Grantee: Millena Volpe Pereira
• Host Institution: Centro Universitário Faculdades Integradas de Ourinhos. Fundação Educacional Miguel Mofarrej. Ourinhos , SP, Brazil

Abstract

Physical properties such as electricity and magnetism are extremely dependent on the processing of materials. In this sense, the method of synthesis chosen directly influences the study of the behavior of certain compounds against electric and magnetic fields. The structural characterization can provide important data regarding the behavior of certain materials, especially when it comes to magnetism, since it is a fact that the magnetic character of the materials is directly related to its cation arrangement. The Ray Diffraction (XRD) technique is a powerful and widely used tool, proving the effectiveness of the synthesis method and providing information about the species arrangement and structural parameters. In the sense of enhancing the XRD technique there are methods of structural refinements, such as the Rietveld Method (MR), which is of great reliability and acceptance in the scientific environment. The MR is highlighted in the refinement of structures that have cationic distribution and whose physical properties depend on this arrangement. MR is based on obtaining a mathematical model built from structural information derived from a database and from the structural information of the XRD profile. Such a theoretical model allows refinement to be made until parameters of method quality are satisfactory. This work aims to study the Rietveld Method and to use the Fullprof Suite Program to perform the structural refinement of the Co3O4 oxide compound, which has Co2+ and Co3+ cations occupying specific positions of a spinel structure and whose understanding of its structural parameters reflect directly on its magnetic properties.