#TITLE_ALTERNATIVE#

• Main Author: RESTU FARDIAN SUWANDI (NIM : 20211307) ; Pembimbing Dr. Siti Nurul Khotimah, M.Sc , Dr.rer.nat, GALIH
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/18534
• Institution: Institut Teknologi Bandung

Nuclear Magetic Resonance (NMR) has been used as research tool in many field. In this study, we investigated magnetic properties, especially antiferromagnetic properties of FeF3 materials. We used zero-field NMR method for investigated of antiferromagnetic properties in this material. We used custom-built NMR from Magnetic Resonance and Magnetism Laboratory, KAIST. The experiment has done by variating sample temperature from 8 K to 220 K. We used ordinary spin echo pulse sequence 90⁰RF–τ–180⁰RF. Using FFT, we analyzed the signal in NMR spectrum and the peak will shown the resonance frequence. The result showed that resonance frequency decrease with temperature increase. The spectrum was positioned around 85.41 MHz in the zero-temperature limit, this showed that Fe hyperfine field at zero-temperatur limit was 2.14 T. The temperature dependence of the local magnetization does not fit T2 very well but instead fit the exponential form applicable when there is an energy gap in the dispersion relation of the spin wave. From this result we can sure that FeF3 is antiferromagnetic material. From the fitting, we obtained an energy gap of 11.466 meV and an anisotropy energy of 1.045 meV.