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内容記述 |
In our daily lives, electromagnetic waves such as visible light, microwaves, and X-rays have become indispensable. One of the key phenomena related to the microwave absorption of magnetic materials is ferromagnetic resonance (FMR). FMR measurements are essential for understanding magnetization dynamics and crucial for developing spintronics devices. This study aims to enable the observation of FMR cost-effectively. Recently, vector network analyzers (VNA) have been widely used for broadband FMR measurements; however, VNAs are prohibitively expensive. To address this issue, we developed an FMR measurement system using NanoVNA, an affordable vector network analyzer readily available on platforms such as Amazon. The NanoVNA is capable of measuring up to 3 GHz, making it suitable for many FMR experiments. Although NanoVNA’s application to physical property measurements, such as high-frequency permittivity, is still in its infancy [1], it holds significant potential. In this study, FMR measurements were performed on Y₃Fe₅O₁₂ (YIG) thin films with a thickness of approximately 2 μm grown on Gd₃Ga₅O₁₂ (GGG) substrates. Fig. 1 shows magnetic field dependence of FMR spectra of the YIG thin film measured using NanoVNA. The measurements were conducted at room temperature, with the magnetic field applied in the film plane. A dip in the transmission coefficient (S21) corresponding to absorption was observed, which shifted to higher frequencies with increasing magnetic field. This confirms that the observed phenomenon is FMR. In this presentation, we will also introduce cost-reducing strategies, including the use of 3D-printed components.[1] A. Erkoreka and J. Martinez-Perdiguero, Rev. Sci. Instrum. 95, 023903 (2024). |
