Simulation of the Electrical Behavior of Thin Anisotropic Conductors.

• Grant number: 22/15559-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2023
• End date: January 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Carlos Alberto Moreira dos Santos
• Grantee: Larissa Comuni Coelho
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil

Abstract

Isotropic materials, such as most metals and anisotropic materials, such as many oxide conductors, organic materials and several superconductors, require methods for characterizing the electrical resistivity. The samples, typically used in this type of study, are often small and/or have irregular shapes, which make difficult to use the traditional methods, such as the standard 4-probe method. In this project, we intend to continue the research carried out over the last 20 years, aiming to improve methods for measuring electrical properties in anisotropic systems, such as superconducting cuprates (2D) and quasi-one-dimensional systems (1D) such as Li0,9Mo6O17 and SrNbO3,41. Recently, the study of the electrical properties of single crystals of SrTiO3-d, which exhibit cubic-tetragonal transition, allowed studying the transitions from an isotropic system to a system starting to show anisotropy. During this study, we realized that the Montgomery Method, modified by our group in 2011, is linked to the van der Pauw method for samples of arbitrary shape. This yielded an analytical method that allows calculating the electrical resistivity of small-sized samples of regular or arbitrary shape, which was recently published in Scientific Reports. In addition, the mentioned work provided several tips, which allow the development of a more general method for the study of the electrical properties of anisotropic samples of any geometry. Thus, one of our group's research projects seeks to continue previous work, using analytical mathematical methods, computer simulations, and measurements of electrical resistivity in isotropic and anisotropic conductors. Preliminary results obtained by simulations demonstrate how the systematic study allows obtaining a simpler and more accurate method. It is worth mentioning that the simulation allows the visualization of field lines and equipotential lines, and provides agility in the study of the physical properties involved in the process with great precision and for samples of different formats, which is not simple to be carried out experimentally. Particularly, this scientific initiation project intends to continue the simulation studies, trying to understand how are the equipotential and electric field lines of thin anisotropic samples with two components of different electrical resistivity.