We have extended the technique of nuclear inelastic scattering to the 25.65
1 keV nuclear transition of Dy-161. Energy spectra of nuclear inelastic abs
orption of synchrotron radiation in Dy-161 metal foil were measured at room
temperature and at T = 15 K with 1.0 meV resolution. From low temperature
data a density of phonon states and several thermodynamic parameters were d
erived.