The data of the article “Development of synchrotron radiation phase- time-resolved X-ray ferromagnetic resonance ”

This dataset mainly includes the phase delay scans of the XFMR system at the Fe L3 edge at frequencies of 0.5 GHz, 2 GHz, 4 GHz, and 6 GHz at the corresponding resonant fields (File 1), the phase delay scan at 0.5 GHz under a fixed bias magnetic field (File 2), and the high-precision fitting and residual analysis at 6 GHz (File 3). File 1 corresponds to Figure 7 in the main text. Under the combined effect of the microwave magnetic field and the constant magnetic field, the electron spin magnetic moment continuously precesses around the effective magnetic field, and the component of the magnetic moment along the X-ray direction oscillates periodically. The experimental data were fitted with a sine curve, showing a periodicity of 2000 ps and its 1/N (N = frequency f/0.5 GHz) corresponding to the excitation frequency. This sinusoidal waveform reflects the oscillatory characteristics of the precession motion. File 2 corresponds to Figure 8 in the main text, which is the phase delay scan at 0.5 GHz under a fixed bias magnetic field. Each group of scans was completed within a fixed bias magnetic field range, and the curves show a clear oscillation with a period of approximately 2000 ps, corresponding to the excitation frequency of the applied microwave at 0.5 GHz. Each curve was fitted with a sine function to extract the precession amplitude (Figure 8b) and phase (Figure 8c) at the corresponding magnetic field. File 3 corresponds to Figure 9 in the main text, which is the high-precision fitting and residual analysis at an excitation frequency of 6 GHz to quantify the phase time resolution capability of the system. According to the fitting, the amplitude A is 196 fA, and the noise standard baseline noise_std is 30 fA (the red dashed line in Figure 9 serves as an auxiliary line), resulting in an SNR of 6.51. Figures 1-6 in the article are schematic diagrams of the setup principle, physical devices, and waveguide simulation visualization, so the dataset for these figures is not provided.