Simulation and Parameterization by the Finite Element Method of a C Shape Delectromagnet for Application in the Characterization of Magnetic Properties of Materials

This article presents the simulation, parameterization and optimization of an electromagnet with the C–shaped configuration, intended for the study of magnetic properties of materials. The electromagnet studied consists of a C-shaped yoke, which provides self–shielding for minimizing losses of magnetic flux density, two poles of high magnetic permeability and power coils wound on the poles. The main physical variable studied was the static magnetic flux density in a column within the gap between the poles, with 4cm of square cross section and a length of 5cm, seeking a suitable set of parameters that allow us to achieve a uniform magnetic flux density of 1x10 Gaussor values above this in the column, when the system operates at room temperature and with a current consumption not exceeding 5A. By means of a magnetostatic analysis by the finite element method, the magnetic flux density and the distribution of the magnetic field lines were visualized and quantified. From the results obtained by simulating an initial configuration of electromagnet, a structural optimization of the geometry of the adjustable caps for the ends of the poles was performed. The magnetic permeability effect of the soft magnetic materials used in the poles system, such as low– carbon steel (0.08% C), Permalloy (45% Ni, 54.7% Fe) and Mumetal (21.2% Fe, 78.5% Ni), was also evaluated. The intensity and uniformity of the magnetic field in the gap showed a high dependence with the factors described above. The magnetic field achieved in the column was uniform and its magnitude ranged between 1.5x10 Gauss and 1.9x10 Gauss according to the material of the pole used, with the possibility of increasing the magnetic field by choosing a suitable geometry of the cap, introducing a cooling system for the coils and adjusting the spacing between the poles. This makes the device a versatile and scalable tool to generate the magnetic field necessary to perform magnetic characterization of materials by techniques such as vibrating sample magnetometry (VSM), Hall-effect, Kerr-effect magnetometry, among others. Additionally, a CAD design of the modules of the electromagnet is presented in order to facilitate the construction and scaling of the physical device. Keywords—Electromagnet, Finite Elements Method, Magnetostatic, Magnetometry, Modeling. A. A Velásquez is with the Departamento de Ciencias Básicas, Grupo Electromagnetismo Aplicado, Universidad EAFIT, Medellín, Colombia, Cra 49 No7 Sur -50 (phone: (57)(4)2619500 Ext 9046; fax: (57)(4)4489500; (email: [email protected]). J.Baena is with the Departamento de Ciencias Básicas, Grupo Electromagnetismo Aplicado, Universidad EAFIT, Medellín, Colombia, Cra 49 No7 Sur -50 (e-mail: [email protected]).