L-edge spectroscopy of dilute, radiation-sensitive systems using a transition-edge-sensor array

We present X-ray absorption spectroscopyand resonant inelastic X-ray scattering(RIXS) measurements on the iron L-edge of 0.5 mM aqueous ferricyanide. These measurements demonstrate the ability of high-throughput transition-edge-sensor(TES) spectrometersto access the rich soft X-ray(100–2000 eV) spectroscopy regime for dilute and radiation-sensitivesamples. Our low-concentration data are in agreement with high-concentration measurements recorded by grating spectrometers. These results show that soft-X-rayRIXS spectroscopy acquired by high-throughput TES spectrometerscan be used to study the local electronic structure of dilute metal-centered complexes relevant to biology, chemistry, and catalysis. In particular, TES spectrometershave a unique ability to characterize frozen solutions of radiation- and temperature-sensitive samples.