X-Ray Detected Ferromagnetic Resonance Spectrometer with an Out-of-Vacuum Photodetector

Abstract

X-ray detected ferromagnetic resonance (XFMR) spectroscopy is an experimental technique for element-specific spin dynamics in the GHz regime and has been utilized to study spintronic materials. The XFMR signal is usually obtained by detecting X-ray excited optical luminescence (XEOL) emitted from a sample substrate. Here, we report the development of an XFMR spectrometer that is designed to place a photodetector for XEOL detection outside an ultra-high-vacuum chamber. This configuration allows for the easy replacement of detectors, such as photodiodes, CCD cameras, and spectrometers, depending on the experimental requirements. We demonstrated the measurement of XEOL spectra from MgO using a visible light spectrometer as well as the detection of XFMR signals originating from the spin precession of a permalloy (Ni₈₀Fe₂₀) thin film using a photodiode detector. The XFMR spectrometer with an out-of-vacuum photodetector expands possibilities for advanced measurements such as XFMR microscopy.