161Dy Synchrotron-Radiation-Based Mössbauer Absorption Spectroscopy

We successfully developed the measurement system for the synchrotron-radiation-based Mössbauer absorption spectra with 161Dy using the 25.7 keV nuclear first excited state. The Mössbauer spectra of DyF3, Dy metal and DyPc2 (Pc = phthalocyanine) were obtained and parameters of hyperfine structure of 161Dy nuclei in them were evaluated as the feasibility study of this method. Isomer shifts showed that Dy atoms in all of them are in trivalent state although those in Dy metal was in the region of trivalent metal region. The magnetic hyperfine field of Dy metal of 569±1 T agreed with the literature of the Mössbauer experiments. That of DyPc2 of 489±1 T was reasonable because the ground state of DyPc2 were in the state of Jz=±13/2. Considering the highly penetrative nature of the 25.7 keV inciden