161Dy synchrotron-radiation-based Mossbauer absorption spectroscopy

We demonstrate a measurement system for synchrotron-radiation-based Mossbauer absorption spectra with Dy-161 using the 25.7 keV nuclear first excited state. Mossbauer spectra of DyF3, Dy metal and DyPc2 (Pc = phthalocyaninato) were obtained and the parameters for the hyperfine structure of Dy-161 nuclei in them were evaluated to demonstrate the feasibility 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 Mossbauer experiments. That of DyPc2 of 489 +/- 1 T was reasonable because the ground state of DyPc2 were in the state of J(z) = +/- 13/2. Considering the highly penetrative nature of the 25.7 keV incident radiation, it will be straightforward to apply this method for the study of materials under various conditions such as high pressure, high magnetic fields, and reactive atmospheres.