We performed nuclear forward and inelastic scattering of synchrotron radiation by elemental Os utilizing the nuclear excited state of ${}^{187}\mathrm{Os}$ which is otherwise inaccessible using any practical radioactive decay process. The lifetime of the excited state, $3.06\left(8\right)\text{ns}$, and the energy of the transition, $9.778\left(3\right)\text{keV}$, are refined. The nuclear quadrupole moment of the excited state, $Q_{3/2}=1.46\left(10\right)\text{b}$, is determined. The density of phonon states for elemental Os, which is herein experimentally determined, suggests that the Os lattice is a model for the lattice dynamics of hcp-Fe. The combination of the low energy of the nuclear transition and the large nuclear mass leads to a high recoil free fraction, $f_{LM}=0.95\left(1\right)$, at room temperature, a large value that strongly supports the viability of nuclear resonance scattering as a reliable method to study electronic, magnetic, and elastic properties of Os compounds, including Os organometallics.

• Received 3 April 2015
• Revised 7 May 2015

DOI:https://doi.org/10.1103/PhysRevB.91.224102