FERROMAGNETIC RESONANCE IN BULK POLYCRYSTAL YTTRIUM IRON GARNET (Y3FE5O12)

• Main Author: Salam, Syafitra
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/78253
• Institution: Institut Teknologi Bandung

Magnonic device utilizes the spin wave to store and process information more efficiently than electronic devices. The performance of this device is affected by the magnetic properties of materials such as gyromagnetic ratio, saturation magnetization, magnetic anisotropy field, and Gilbert damping parameter. All of these quantities can be obtained by observing the ferromagnetic resonance phenomenon in a material. Thus, the FMR measurement need to be done to determine the material that is suitable for the magnonic devices. In this final project, the FMR simulations and experiments for yttrium iron garnet (YIG) Y3Fe5O12 have been done. The simulations are done by using Ansys HFSS trial version and the experiments are done by emitting the microwave using vector network analyzer (VNA). Various experimental variations were done such as transmission line variations (backed ground coplanar waveguide and microstrip line), sample thickness (1,6, 1,08, and 0,60 mm), and the direction of the external magnetic field (parallel to the microwave magnetic field and perpendicular to microwave magnetic field). The simulation and experiment results give the ????21 (transmittance) vs frequency curves. In the resulting curves for MSL and backed ground CPW, the absorption curve shifts to a higher value with the increase in the sample’s internal magnetic field at a certain frequency (FMR frequency) which indicates the FMR phenomenon. The FMR frequencies are plotted against the magnetic field and the FMR fitting is done by the Kittel mode. Based on the experimental results, the configuration that gives the best FMR values is a YIG thickness of 0,60 mm on a backed ground coplanar waveguide with an external magnetic field direction parallel to the sample and a microwave magnetic field.